RESUMO
Bacteria-infected wounds pose challenges to healing due to persistent infection and associated damage to nerves and vessels. Although sonodynamic therapy can help kill bacteria, it is limited by the residual oxidative stress, resulting in prolonged inflammation. To tackle these barriers, novel 4 octyl itaconate-coated Li-doped ZnO/PLLA piezoelectric composite microfibers are developed, offering a whole-course "targeted" treatment under ultrasound therapy. The inclusion of Li atoms causes the ZnO lattice distortion and increases the band gap, enhancing the piezoelectric and sonocatalytic properties of the composite microfibers, collaborated by an aligned PLLA conformation design. During the infection and inflammation stages, the piezoelectric microfibers exhibit spatiotemporal-dependent therapeutic effects, swiftly eliminating over 94.2 % of S. aureus within 15 min under sonodynamic therapy. Following this phase, the microfibers capture reactive oxygen species and aid macrophage reprogramming, restoring mitochondrial function, achieving homeostasis, and shortening inflammation cycles. As the wound progresses through the healing stages, bioactive Zn2+ and Li + ions are continuously released, improving cell recruitment, and the piezoelectrical stimulation enhances wound recovery with neuro-vascularization. Compared to commercially available dressings, our microfibers accelerate the closure of rat wounds (Φ = 15 mm) without scarring in 12 days. Overall, this "one stone, four birds" wound management strategy presents a promising avenue for infected wound therapy.
Assuntos
Terapia por Ultrassom , Cicatrização , Animais , Cicatrização/efeitos dos fármacos , Terapia por Ultrassom/métodos , Ratos Sprague-Dawley , Ratos , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/química , Camundongos , Estimulação Elétrica , Masculino , Infecções Estafilocócicas/terapia , Poliésteres/química , Espécies Reativas de Oxigênio/metabolismo , Terapia por Estimulação Elétrica/métodos , Neovascularização Fisiológica/efeitos dos fármacosRESUMO
Poly(butylene succinate-co-furandicarboxylate) (PBSF) and poly(butylene adipate-co-furandicarboxylate) (PBAF) are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate) (PBST) and poly(butylene adipate-co-terephthalate) (PBAT). In this study, quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradation mechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B (CALB). Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism, with the initial two steps being acylation reactions and the subsequent two being hydrolysis reactions. Notably, the first step of the hydrolysis is identified as the rate-determining step. Moreover, by introducing single-point mutations to expand the substrate entrance tunnel, the catalytic distance of the first acylation step decreases. Additionally, energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme's active site. This study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme's active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB.
Assuntos
Proteínas Fúngicas , Lipase , Poliésteres , Lipase/metabolismo , Lipase/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/química , Poliésteres/química , Poliésteres/metabolismo , Biodegradação Ambiental , Simulação de Dinâmica Molecular , Hidrólise , Modelos QuímicosRESUMO
Polylactic acid (PLA) straws hold eco-friendly potential; however, residual diisocyanates used to enhance the mechanical strength can generate carcinogenic primary aromatic amines (PAAs), posing health risks. Herein, we present a rapid, comprehensive strategy to detecting PAAs in 18 brands of food-grade PLA straws and assessing their migration into diverse food simulants. Surface-enhanced Raman spectroscopy was conducted to rapidly screen straws for PAAs. Subsequently, qualitative determination of migrating PAAs into various food simulants (4 % acetic acid, 10 % ethanol, 50 % ethanol) occurred at 70 °C for 2 h using liquid chromatography-mass spectrometry. Three PAAs including 4,4'-methylenedianiline, 2,4'-methylenedianiline, and 2,4-diaminotoluene were detected in all straws. Specifically, 2,4-diaminotoluene in 50 % ethanol exceeded specific migration limit of 2 µg/kg, raising safety concerns. Notably, PAAs migration to 10 % and 50 % ethanol surpassed that to 4 % acetic acid within a short 2-hour period. Moreover, PLA straws underwent varying degrees of shape changes before and after migration. Straws with poly(butylene succinate) resisted deformation compared to those without, indicating enhanced heat resistance, while poly(butyleneadipate-co-terephthalate) improved hydrolysis resistance. Importantly, swelling study unveiled swelling effect wasn't the primary factor contributing to the increased PAAs migration in ethanol food simulant, as there was no significant disparity in swelling degrees across different food simulants. FT-IR and DSC analysis revealed higher PAAs content in 50 % ethanol were due to highly concentrated polar ethanol disrupting hydrogen bonds and van der Waal forces holding PLA molecules together. Overall, minimizing contact between PLA straws and alcoholic foods is crucial to avoid potential safety risks posed by PAAs.
Assuntos
Aminas , Poliésteres , Análise Espectral Raman , Poliésteres/química , Análise Espectral Raman/métodos , Cromatografia Líquida/métodos , Aminas/análise , Aminas/química , Espectrometria de Massas/métodos , Contaminação de Alimentos/análise , Embalagem de Alimentos , Espectrometria de Massa com Cromatografia LíquidaRESUMO
BACKGROUND: The use of mobilizing agents for hematopoietic stem cell (HSC) transplantation is insufficient for an increasing number of patients. We previously reported lipid made endocannabinoid (eCB) ligands act on the human bone marrow (hBM) HSC migration in vitro, lacking long term stability to be therapeutic candidate. In this study, we hypothesized if a novel 2-AG-loaded polycaprolactone (PCL)-based nanoparticle delivery system that actively targets BM via phosphatidylserine (Ps) can be generated and validated. METHODS: PCL nanoparticles were prepared by using the emulsion evaporation method and characterized by Zetasizer and scanning electron microscopy (SEM). The encapsulation efficiency and release profile of 2-AG were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The presence of cannabinoid receptors (CBRs) in HSCs and monocytes was detected by flow cytometry. Cell morphology and viability were assessed using transmission electron microscopy (TEM), SEM, and the WST-1 viability assay. The migration efficacy of the 2-AG and 2-AG-loaded nanoparticle delivery system on HSCs and HPSCs (TF-1a and TF-1) and monocytes (THP-1) was evaluated using a transwell migration assay. RESULTS: The 140-225 nm PCL nanoparticles exhibited an increasing polydispersity index (PDI) after the addition of Ps and 2-AG, with a surface charge ranging from - 25 to -50 mV. The nanoparticles released up to 36% of 2-AG within the first 8 h. The 2-AG-Ps-PCL did not affect cellular viability compared to control on days 5 and 10. The HSCs and monocytes expressed CB1R and CB2R and revealed increased migration to media containing 1 µM 2-AG-Ps-PCL compared to control. The migration rate of the HSCs toward monocytes incubated with 1 µM 2-AG-Ps-PCL was higher than that of the monocytes of control. The 2-AG-Ps-PCL formulation provided a real time mobilization efficacy at 1 µM dose and 8 h time window via a specific CBR agonism. CONCLUSION: The newly generated and validated 2-AG-loaded PCL nanoparticle delivery system can serve as a stable, long lasting, targeted mobilization agent for HSCs and as a candidate therapeutic to be included in HSC transplantation (HSCT) protocols following scale-up in vivo preclinical and subsequent clinical trials.
Assuntos
Células-Tronco Hematopoéticas , Nanopartículas , Poliésteres , Humanos , Poliésteres/química , Nanopartículas/química , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/citologia , Movimento Celular/efeitos dos fármacos , Endocanabinoides/farmacologia , Medula Óssea/metabolismo , Medula Óssea/efeitos dos fármacosRESUMO
D-xylose, one of the most abundant sugars in lignocellulosic biomass, is not widely used to produce bioproducts with added value, in part due to the absence of industrial microorganisms able to metabolize it efficiently. Herbaspirillum seropedicae Z69 is a ß-proteobacterium able to accumulate poly-3-hydroxybutyrate, a biodegradable thermoplastic biopolymer, with contents higher than 50%. It metabolizes D-xylose by non-phosphorylative pathways. In the genome of Z69, we found the genes xylFGH (ABC D-xylose transporter), xylB, xylD, and xylC (superior non-phosphorylative pathway), and the transcriptional regulator xylR, forming the xyl cluster. We constructed the knock-out mutant Z69ΔxylR that has a reduced growth in D-xylose and in D-glucose, compared with Z69. In addition, we analyzed the expression of xyl genes by RT-qPCR and promoter fusion. These results suggest that XylR activates the expression of genes at the xyl cluster in the presence of D-xylose. On the other hand, XylR does not regulate the expression of xylA, mhpD (lower non-phosphorylative pathways) and araB (L-arabinose dehydrogenase) genes. The participation of D-glucose in the regulation mechanism of these genes must still be elucidated. These results contribute to the development of new strains adapted to consume lignocellulosic sugars for the production of value-added bioproducts.
Assuntos
Proteínas de Bactérias , Regulação Bacteriana da Expressão Gênica , Herbaspirillum , Família Multigênica , Xilose , Xilose/metabolismo , Herbaspirillum/genética , Herbaspirillum/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Poliésteres/metabolismo , Hidroxibutiratos/metabolismo , Glucose/metabolismo , Regiões Promotoras Genéticas , Poli-HidroxibutiratosRESUMO
A Gram-stain-negative, strictly aerobic, motile, flagellated, rod-shaped, halotolerant, and poly-ß-hydroxyalkanoate-producing bacterium, designated DP4N28-3T, was isolated from offshore sediment surrounding hard coral in the Dapeng peninsula (Guangdong, PR China). Growth occurred at 15-35â°C (optimal at 30â°C), pH 6.0-9.5 (optimal at 6.0-7.0), and 0.0-30.0â% NaCl concentration (w/v, optimal at 0.0-2.0â%), showing halotolerance. Phylogeny based on 16S rRNA gene sequences, five housekeeping genes, and genome sequences identified Pseudohoeflea suaedae DSM 23348T (98.1â%, 16S rRNA gene sequence similarity) as the most related species to strain DP4N28-3T. Average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values between strain DP4N28-3T and P. suaedae DSM 23348T were all below the threshold of species demarcation. Major phenotypic differences were the flagella type and the limited sources of single carbon utilization by strain DP4N28-3T, which only included acetic acid, acetoacetic acid, d-glucuronic acid, and glucuronamide. Strain DP4N28-3T harboured the class I poly-ß-hydroxyalkanoate synthase gene (phaC) and produced poly-ß-hydroxybutyrate. The fatty acids were summed feature 8 (C18â:â1 ω6c and/or C18â:â1 ω7c, 49.4â%) and C16â:â0 (13.4â%). The major cellular polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, and sulfoquinovosyl diacylglycerol. The respiratory quinone was Q-10. The results of the phylogenetic, genomic, phenotypic, and chemotaxonomic analysis indicated that the isolated strain represents the type strain of a novel species. Based on these results, strain DP4N28-3T (=MCCC 1K05639T=KCTC 82803T) is proposed as the type strain of the novel species Pseudohoeflea coraliihabitans sp. nov.
Assuntos
Antozoários , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Sedimentos Geológicos , Hidroxibutiratos , Hibridização de Ácido Nucleico , Filogenia , Poliésteres , RNA Ribossômico 16S , Análise de Sequência de DNA , RNA Ribossômico 16S/genética , China , Hidroxibutiratos/metabolismo , DNA Bacteriano/genética , Poliésteres/metabolismo , Sedimentos Geológicos/microbiologia , Animais , Antozoários/microbiologia , Poli-HidroxibutiratosRESUMO
China's polyester textile industry is one of the notable contributors to national economy. This paper takes polyester yarn, core raw material in polyester textile industry chain, as research object, and deeply explores its price indicators and risk hedging mechanisms through multiple linear regression models and Holt-Winters approaches. It is worth mentioning that with continuous development of digital technology, digital transformation of production lines and warehouses has become an important development feature in various industries. This study also actively complies with this trend, and innovatively incorporates the upstream and downstream production line start-up rates into price prediction model. Through this initiative, we can more comprehensively consider the impact of supply and demand changes on price of polyester yarn, thus making prediction results more closely reflect the actual market situation. This quantitative analysis method undoubtedly provides new ideas for enterprises to better grasp market dynamics in digital era.
Assuntos
Poliésteres , Poliésteres/química , Modelos Lineares , Indústria Têxtil , Comércio/economia , China , TêxteisRESUMO
BACKGROUND: The integration of stem cells, signaling molecules, and biomaterial scaffolds is fundamental for the successful engineering of functional bone tissue. Currently, the development of composite scaffolds has emerged as an attractive approach to meet the criteria of ideal scaffolds utilized in bone tissue engineering (BTE) for facilitating bone regeneration in bone defects. Recently, the incorporation of polycaprolactone (PCL) with hydroxyapatite (HA) has been developed as one of the suitable substitutes for BTE applications owing to their promising osteogenic properties. In this study, a three-dimensional (3D) scaffold composed of PCL integrated with HA (PCL/HA) was prepared and assessed for its ability to support osteogenesis in vitro. Furthermore, this scaffold was evaluated explicitly for its efficacy in promoting the proliferation and osteogenic differentiation of canine bone marrow-derived mesenchymal stem cells (cBM-MSCs) to fill the knowledge gap regarding the use of composite scaffolds for BTE in the veterinary orthopedics field. RESULTS: Our findings indicate that the PCL/HA scaffolds substantially supported the proliferation of cBM-MSCs. Notably, the group subjected to osteogenic induction exhibited a markedly upregulated expression of the osteogenic gene osterix (OSX) compared to the control group. Additionally, the construction of 3D scaffold constructs with differentiated cells and an extracellular matrix (ECM) was successfully imaged using scanning electron microscopy. Elemental analysis using a scanning electron microscope coupled with energy-dispersive X-ray spectroscopy confirmed that these constructs possessed the mineral content of bone-like compositions, particularly the presence of calcium and phosphorus. CONCLUSIONS: This research highlights the synergistic potential of PCL/HA scaffolds in concert with cBM-MSCs, presenting a multidisciplinary approach to scaffold fabrication that effectively regulates cell proliferation and osteogenic differentiation. Future in vivo studies focusing on the repair and regeneration of bone defects are warranted to further explore the regenerative capacity of these constructs, with the ultimate goal of assessing their potential in veterinary clinical applications.
Assuntos
Regeneração Óssea , Durapatita , Células-Tronco Mesenquimais , Osteogênese , Poliésteres , Alicerces Teciduais , Animais , Cães , Poliésteres/química , Poliésteres/farmacologia , Alicerces Teciduais/química , Osteogênese/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Células-Tronco Mesenquimais/fisiologia , Regeneração Óssea/efeitos dos fármacos , Proliferação de Células , Diferenciação Celular/efeitos dos fármacos , Engenharia Tecidual/métodosRESUMO
Chronic wounds represent a significant global health concern, statistically impacting 1-2% of the population in developed countries throughout their lifetimes. These wounds cause considerable discomfort for patients and necessitate substantial expenditures of time and resources for treatment. Among the emerging therapeutic approaches, medicated dressings incorporating bioactive molecules, including natural compounds, are particularly promising. Hence, the objective of this study was to develop novel antimicrobial dressings for wound treatment. Specifically, polycaprolactone membranes were manufactured using the electrospinning technique and subsequently coated with natural polyelectrolytes (chitosan as a polycation and a mixture of manuka honey with essential oils nanoemulsions as a polyanion) employing the Layer-by-Layer assembly technique. Physico-chemical and morphological characterization was conducted through QCM-D, FTIR-ATR, XPS, and SEM analyses. The results from SEM and QCM-D demonstrated successful layer deposition and coating formation. Furthermore, FTIR-ATR and XPS analyses distinguished among different coating compositions. The coated membranes were tested in the presence of fibroblast cells, demonstrating biocompatibility and expression of genes coding for VEGF, COL1, and TGF-ß1, which are associated with the healing process (assessed through RT-qPCR analysis). Finally, the membranes exhibited excellent antibacterial activity against both Staphylococcus aureus and Pseudomonas aeruginosa, with higher bacterial strain inhibition observed when cinnamon essential oil nanoemulsion was incorporated. Taken together, these results demonstrate the potential application of nanocoated membranes for biomedical applications, such as wound healing.
Assuntos
Mel , Óleos Voláteis , Poliésteres , Cicatrização , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Cicatrização/efeitos dos fármacos , Poliésteres/química , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Membranas Artificiais , Leptospermum/química , Bandagens , Staphylococcus aureus/efeitos dos fármacos , Quitosana/química , Quitosana/farmacologia , Fibroblastos/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Polieletrólitos/químicaRESUMO
BACKGROUND: A quasi-experimental comparative trial will be designed in Burkina Faso. The study will compare the use and preferences for two groups types of insecticide-treated nets textile: polyester-based and polyethylene-based, according to their use and preferences in selected health districts. These health districts will be selected in three eco-climate zones (Sahelian, dry savannah and wet savannah) in the country. These findings will inform decisions on future net procurements for national malaria control programme in 2025. METHODS: Quantitative surveys and qualitative data collection will be carried out to gather information on the type of net textile most commonly used and preferred by the community. They will be performed between the end of the dry season and the early rainy season. The quantitative surveys involved household interviews with households and individuals' questionnaires, while the qualitative data collection involved in-depth individual interviews and focus group discussions to explore and clarify some key evaluation criteria. A total of 9450 insecticide-treated nets were surveyed for quantitative survey purposes. For the qualitative study, 48 in-depth individual interviews and 12 focus group discussions were carried out. A mixed model approach combining the results from quantitative surveys and qualitative studies will be used for decision-making on the type of insecticide-treated net preference. CONCLUSION: This methodological approach will be used by the National Malaria Control Programme to conduct this study on determinants of net use in Burkina Faso in order to provide robust evidence across diverse settings. This mixed-methods approach for data collection and analysis could be used in other countries to provide evidence that would help to increase the uptake of insecticide-treated nets, the main vector control tool in Africa.
Assuntos
Características da Família , Mosquiteiros Tratados com Inseticida , Malária , Controle de Mosquitos , Burkina Faso , Malária/prevenção & controle , Humanos , Controle de Mosquitos/métodos , Controle de Mosquitos/estatística & dados numéricos , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Polietileno , Poliésteres , Tomada de Decisões , Têxteis , Inquéritos e QuestionáriosRESUMO
Although extensive research has been conducted on the environmental impact of microplastics (MPs), their effects on microorganisms during the composting process and on the compost-soil system remain unclear. Our research investigates the microbial response to polylactic acid microplastics (PLAMPs) during aerobic composting and examines how compost enriched with PLAMPs affects plants. Our findings reveal that PLAMPs play a dual role in the composting process, influencing microorganisms differently depending on the composting phase. PLAMPs reduce the relative abundance of sensitive bacterial ASVs, specifically those belonging to Limnochordaceae and Enterobacteriaceae, during composting, while increasing the relative abundance of ASVs belonging to Steroidobacteriaceae and Bacillaceae. The impact of PLAMPs on microbial community assembly and niche width was found to be phase-dependent. In the stabilization phase (S5), the presence of PLAMPs caused a shift in the core microbial network from bacterial dominance to fungal dominance, accompanied by heightened microbial antagonism. Additionally, these intricate microbial interactions can be transferred to the soil ecosystem. Our study indicates that composting, as a method of managing PLAMPs, is also influenced by PLAMPs. This influence is transferred to the soil through the use of compost, resulting in severe oxidative stress in plants. Our research is pivotal for devising future strategies for PLAMPs management and predicting the subsequent changes in compost quality and environmental equilibrium.
Assuntos
Bactérias , Compostagem , Microplásticos , Poliésteres , Microbiologia do Solo , Poluentes do Solo , Microplásticos/toxicidade , Poliésteres/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Poluentes do Solo/metabolismo , Bactérias/metabolismo , Bactérias/classificação , Ecossistema , Microbiota/efeitos dos fármacos , Fungos/metabolismo , Solo/química , Plantas/metabolismo , Plantas/efeitos dos fármacosRESUMO
Implant-related infections pose significant challenges to orthopedic surgeries due to the high risk of severe complications. The widespread use of bioactive prostheses in joint replacements, featuring roughened surfaces and tight integration with the bone marrow cavity, has facilitated bacterial proliferation and complicated treatment. Developing antibacterial coatings for orthopedic implants has been a key research focus in recent years to address this critical issue. Researchers have designed coatings using various materials and antibacterial strategies. In this study, we fabricated 3D-printed porous titanium rods, incorporated vancomycin-loaded mPEG750-b-PCL2500 gel, and coated them with a PCL layer. We then evaluated the antibacterial efficacy through both in vitro and in vivo experiments. Our coating passively inhibits bacterial biofilm formation and actively controls antibiotic release in response to bacterial growth, providing a practical solution for proactive and sustained infection control. This study utilized 3D printing technology to produce porous titanium rod implants simulating bioactive joint prostheses. The porous structure of the titanium rods was used to load a thermoresponsive gel, mPEG750-b-PCL2500 (PEG: polyethylene glycol; PCL: polycaprolactone), serving as a novel drug delivery system carrying vancomycin for controlled antibiotic release. The assembly was then covered with a PCL membrane that inhibits bacterial biofilm formation early in infection and degrades when exposed to lipase solutions, mimicking enzymatic activity during bacterial infections. This setup provides infection-responsive protection and promotes drug release. We investigated the coating's controlled release, antibacterial capability, and biocompatibility through in vitro experiments. We established a Staphylococcus aureus infection model in rabbits, implanting titanium rods in the femoral medullary cavity. We evaluated the efficacy and safety of the composite coating in preventing implant-related infections using imaging, hematology, and pathology. In vitro experiments demonstrated that the PCL membrane stably protects encapsulated vancomycin during PBS immersion. The PCL membrane rapidly degraded at a lipase concentration of 0.2 mg/mL. The mPEG750-b-PCL2500 gel ensured stable and sustained vancomycin release, inhibiting bacterial growth. We investigated the antibacterial effect of the 3D-printed titanium material, coated with PCL and loaded with mPEG750-b-PCL2500 hydrogel, using a rabbit Staphylococcus aureus infection model. Imaging, hematology, and histopathology confirmed that our composite antibacterial coating exhibited excellent antibacterial effects and infection prevention, with good safety in trials. Our results indicate that the composite antibacterial coating effectively protects vancomycin in the hydrogel from premature release in the absence of bacterial infection. The outer PCL membrane inhibits bacterial growth and prevents biofilm formation. Upon contact with bacterial lipase, the PCL membrane rapidly degrades, releasing vancomycin for antibacterial action. The mPEG750-b-PCL2500 gel provides stable and sustained vancomycin release, prolonging its antibacterial effects. Our composite antibacterial coating demonstrates promising potential for clinical application.
Assuntos
Antibacterianos , Hidrogéis , Poliésteres , Impressão Tridimensional , Titânio , Vancomicina , Titânio/química , Vancomicina/farmacologia , Vancomicina/administração & dosagem , Vancomicina/química , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/química , Poliésteres/química , Animais , Hidrogéis/química , Coelhos , Staphylococcus aureus/efeitos dos fármacos , Liberação Controlada de Fármacos , Porosidade , Biofilmes/efeitos dos fármacos , Polietilenoglicóis/química , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/prevenção & controle , Sistemas de Liberação de Medicamentos/métodos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologiaRESUMO
Topical eye drop approaches to treat ocular inflammation in dry eyes often face limitations such as low efficiency and short duration of drug delivery. Nanofibers serve to overcome the limitation of the short duration of action of topical eye drops used against ocular inflammation in dry eyes. Several attempts to develop suitable nanofibers have been made; however, there is no ideal solution. Here, we developed polycaprolactone (PCL) nanofibers loaded with dexamethasone acetate (DEX), prepared by electrospinning, as a potential ocular drug delivery platform for corneal injury treatment. Thirty-nine Sprague Dawley rats (7 weeks old males) were divided into four treatment groups after alkaline burns of the cornea; negative control (no treatment group); dexamethasone eyedrops (DEX group); PCL fiber (PCL group); dexamethasone loaded PCL (PCL + DEX group). We evaluated therapeutic efficacy of PCL + DEX by examining the epithelial wound healing effect, the extent of corneal opacity and neovascularization. Additionally, various inflammatory factors, including IL-1ß, were investigated through immunochemistry, western blot analysis, and quantitative real-time RT-PCR (qRT-PCR). PCL + DEX group showed histologically alleviated signs of corneal inflammation compared with DEX group, which showed a decrease in IL-1ß and MMP9 in the corneal stroma. The quantitative expression on day 1 after alkaline burn of pro-inflammatory markers, including IL-1ß and IL-6, in the PCL + DEX group was significantly lower than that in the DEX group. Notably, PCL + DEX treatment significantly suppressed neovascularization, and enhanced the anti-inflammatory function of DEX during the acute phase of ocular inflammation. Collectively, these findings suggest that PCL + DEX may be a promising approach to effective drug delivery in corneal burn injuries.
Assuntos
Queimaduras Químicas , Dexametasona , Nanofibras , Poliésteres , Ratos Sprague-Dawley , Cicatrização , Animais , Dexametasona/farmacologia , Dexametasona/administração & dosagem , Dexametasona/análogos & derivados , Nanofibras/química , Poliésteres/química , Ratos , Queimaduras Químicas/tratamento farmacológico , Queimaduras Químicas/patologia , Masculino , Cicatrização/efeitos dos fármacos , Queimaduras Oculares/tratamento farmacológico , Queimaduras Oculares/patologia , Queimaduras Oculares/induzido quimicamente , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/química , Lesões da Córnea/tratamento farmacológico , Lesões da Córnea/patologia , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Metaloproteinase 9 da Matriz/metabolismo , Córnea/efeitos dos fármacos , Córnea/metabolismo , Córnea/patologia , Soluções Oftálmicas , Modelos Animais de DoençasRESUMO
A novel near-zero-discharge recirculating aquaculture system was successfully set up and ran for six months or above. A uniquely designed and 3D printed poly (lactic acid) (PLA) structure was applied as carbon source. The system achieved over 50 % daily nitrogen removal capability and maintained a low NO3-N level of <0.5 mg/L. Steady water quality was observed throughout the experiment period. Microbial distribution was studied and top abundant microorganisms and their general functions in carbon and nitrogen utilization were discussed. Denitrification and L-glutamate formation were identified as two main nitrogen pathways. The cooccurrence network connecting various genera and multiple functions was revealed. Subtilisin was one important PLA degrading enzymes in the system.
Assuntos
Aquicultura , Carbono , Nitrogênio , Poliésteres , Impressão Tridimensional , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , DesnitrificaçãoRESUMO
Understanding the environmental fate of biodegradable plastics in aquatic systems is crucial, given the alarming amount of plastic waste and microplastic particles transported through aquatic pathways. In particular, there is a need to analyze the biodegradation of commercialized biodegradable plastics upon release from wastewater treatment plants into natural aquatic systems. This study investigates the biodegradation behaviors of poly(butylene adipate terephthalate) (PBAT) and poly(vinyl alcohol) (PVA) in wastewater, freshwater, and seawater. Biodegradation of PBAT and PVA assessed through biochemical oxygen demand (BOD) experiments and microcosm tests revealed that the type of aquatic system governs the biodegradation behaviors of each plastic, with the highest biodegradation rate achieved in wastewater for both PBAT and PVA (25.6 and 32.2 % in 30 d, respectively). Plastic release pathway from wastewater into other aquatic systems simulated by sequential incubation in different microcosms suggested that PBAT exposed to wastewater and freshwater before reaching seawater was more prone to degradation than when directly exposed to seawater. On the other hand, PVA displayed comparable biodegradation rate regardless of whether it was directly exposed to seawater or had passed through other environments beforehand. Metagenome amplicon sequencing of 16S rRNA genes revealed distinct community shifts dependent on the type of plastics in changing environments along the simulated aquatic pathway. Several bacterial species putatively implicated in the biodegradation of PBAT and PVA are discussed. Our findings underscore the significant influence of pollution routes on the biodegradation of PBAT and PVA, highlighting the potential for wastewater treatment to facilitate rapid degradation compared to direct exposure to pristine aquatic environments.
Assuntos
Biodegradação Ambiental , Poliésteres , Álcool de Polivinil , Águas Residuárias , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Poliésteres/metabolismo , Águas Residuárias/química , Água do Mar/química , Plásticos Biodegradáveis/metabolismoRESUMO
Tissue engineering scaffolds are three-dimensional structures that provide an appropriate environment for cellular attachment, proliferation, and differentiation. Depending on their specific purpose, these scaffolds must possess distinct features, including appropriate mechanical properties, porosity, desired degradation rate, and cell compatibility. This investigation aimed to fabricate a new nanocomposite scaffold using a 3D printing technique composed of poly(ε-caprolactone) (PCL)/Gelatin (GEL)/ordered mesoporous calcium-magnesium silicate (om-CMS) particles. Different weight ratios of om-CMS were added and optimized, and a series of scaffolds were constructed for comparison purposes, including PCL 50%/Gel 50%, PCL 50%/Gel 45%/om-CMS%5, and PCL 50%/Gel 40%/om-CMS%10. The optimized weight ratio of om-CMS was 10% without leaving behind negative effects on the filaments' structure. The scaffolds' physical and chemical properties were assessed using various techniques, and their degradation rate, bioactivity potential, cell viability, attachment, and ALP activity were evaluated in vitro. The results demonstrated that the PCL 50%/Gel 40%/om-CMS10% scaffold had promising potential for further studies in bone tissue regeneration.
Assuntos
Regeneração Óssea , Gelatina , Nanocompostos , Poliésteres , Impressão Tridimensional , Silicatos , Engenharia Tecidual , Alicerces Teciduais , Gelatina/química , Alicerces Teciduais/química , Poliésteres/química , Nanocompostos/química , Regeneração Óssea/efeitos dos fármacos , Engenharia Tecidual/métodos , Silicatos/química , Porosidade , Sobrevivência Celular/efeitos dos fármacos , Silicatos de Magnésio/química , Teste de Materiais , Humanos , Proliferação de Células/efeitos dos fármacos , Compostos de Cálcio/química , Magnésio/química , Materiais Biocompatíveis/química , Osso e Ossos , Animais , Adesão Celular/efeitos dos fármacos , Cálcio/químicaRESUMO
The extensive use of various chemicals in synthetic plastics is toxic and threatens the biosphere. To address this, the study aimed to isolate, screen, characterize, optimize, and quantify polyhydroxybutyrate (PHB)-producing bacteria using cost-effective residues. Isolated from a landfill site, the Gram-positive, rod-shaped, spore-forming, motile bacterium with intracellular PHB granules was identified as Bacillus pacificus based on phenotypic and genotypic characteristics. Optimal PHB production parameters included a nutrient broth medium, 72 h of incubation, a temperature of 37° C, a pH of 7.0, glucose as the carbon source, ammonium chloride as the nitrogen source, and a carbon-to-nitrogen ratio of 4:1, resulting in a 1.42-fold PHB production increase. B. pacificus was also cultured on various low-cost substrates. Among the oil wastes, feedstock showed the highest PHB production (1.983 ± 0.005 g/L) and among agricultural residues, the maximum PHB was obtained from rice bran (1.626 ± 0.01 g/L). UV-visible spectrophotometric, FT-IR, and HR-LCMS analysis of extracted PHB confirmed characteristics of PHB molecules (Ê-max at 210 nm, functional groups between 1152 and 2925 cm-1). The 1H NMR analysis revealed distinct signals for protons resonating at aliphatic CH3 proton groups, bridged CH protons, and shielding CH2 proton regions that matched PHBs. Thermal gravimetric analysis (TGA) and direct scanning colorimetric (DSC) analysis revealed 89.4% degradation and melting temperature at 124.1 °C for the extracted PHB compound.
Assuntos
Bacillus , Hidroxibutiratos , Bacillus/metabolismo , Bacillus/genética , Bacillus/classificação , Hidroxibutiratos/metabolismo , Poliésteres/metabolismo , Poliésteres/química , Nitrogênio/metabolismo , Meios de Cultura/química , Carbono/metabolismo , Temperatura , Concentração de Íons de HidrogênioRESUMO
Hydrogels have emerged as potential materials for bone grafting, thanks to their biocompatibility, biodegradation, and flexibility in filling irregular bone defects. In this study, we fabricated a novel NAH hydrogel system, composed of N,O-carboxymethyl chitosan (NOCC), aldehyde hyaluronic acid (AHA), and hydroxyapatite (HAp). To improve the mechanical strength of the fabricated hydrogel, a porous polycaprolactone (PCL) matrix was synthesized and used as a three-dimensional (3D) support template for NAH hydrogel loading, forming a novel PCL/NAH hybrid scaffold. A mixture of monosodium glutamate (M) and sucrose (S) at varied weight ratios (5M:5S, 7M:3S, and 9M:1S) was used for the fabrication of 3D PCL matrices. The morphology, interconnectivity, and water resistance of the porous PCL scaffolds were investigated for optimal hydrogel loading efficiency. The results demonstrated that PCL scaffolds with porogen ratios of 7M:3S and 9M:1S possessed better interconnectivity than 5M:5S ratio. The compressive strength of the PCL/NAH hybrid scaffolds with 9M:1S (561.6 ± 6.1 kPa) and 7M:3S (623.8 ± 6.8 kPa) ratios are similar to cancellous bone and all hybrid scaffolds were biocompatible. Rabbit models with tibial defects were implanted with the PCL/NAH scaffolds to assess the wound healing capability. The results suggest that the PCL/NAH hybrid scaffolds, specifically those with porogen ratio of 7M:3S, exhibit promising bone healing effects.
Assuntos
Regeneração Óssea , Quitosana , Durapatita , Ácido Hialurônico , Hidrogéis , Poliésteres , Alicerces Teciduais , Quitosana/química , Quitosana/farmacologia , Quitosana/análogos & derivados , Animais , Coelhos , Durapatita/química , Durapatita/farmacologia , Alicerces Teciduais/química , Regeneração Óssea/efeitos dos fármacos , Poliésteres/química , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Teste de Materiais , MasculinoRESUMO
The treatment of irregular-shaped and critical-sized bone defects poses a clinical challenge. Deployable, self-fitting tissue scaffolds that can be implanted by minimally invasive procedures are a promising solution. Toward this, we fabricated NIR-responsive and programmable polylactide-co-trimethylene carbonate (PLMC) scaffolds nanoengineered with polydopamine nanoparticles (PDA) by extrusion-based three-dimensional (3D) printing. The 3D-printed scaffolds demonstrated excellent (>99%), fast (under 30 s), and tunable shape recovery under NIR irradiation. PLMC-PDA composites demonstrated significantly higher osteogenic potential in vitro as revealed by the significantly enhanced alkaline phosphatase (ALP) secretion and mineral deposition in contrast to neat PLMC. Intraoperative deployability and in vivo bone regeneration ability of PLMC-PDA composites were demonstrated, using self-fitting scaffolds in critical-sized cranial bone defects in rabbits. The 3D-printed scaffolds were deformed into compact shapes that could self-fit into the defect shape intraoperatively under low power intensity (0.76 W cm-2) NIR. At 6 and 12 weeks postsurgical implantation, near-complete bone regeneration was observed in PLMC-PDA composites, unlike neat PLMC through microcomputed tomography (micro-CT) analysis. The potential clinical utility of the 3D-printed composites to secure complex defects was confirmed through self-fitting of the scaffolds into irregular defects in ex vivo models of rabbit tibia, mandible, and tooth models. Taken together, the composite scaffolds fabricated here offer an innovative strategy for minimally invasive deployment to fit irregular and complex tissue defects for bone tissue regeneration.
Assuntos
Regeneração Óssea , Indóis , Osteogênese , Polímeros , Impressão Tridimensional , Alicerces Teciduais , Animais , Alicerces Teciduais/química , Coelhos , Regeneração Óssea/efeitos dos fármacos , Polímeros/química , Indóis/química , Osteogênese/efeitos dos fármacos , Poliésteres/química , Nanopartículas/química , Engenharia Tecidual , Dioxanos/química , Raios Infravermelhos , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologiaRESUMO
Metal particles incorporated into polymer matrices in various forms and geometries are attractive material platforms for promoting wound healing and preventing infections. However, the fate of these metal particles and their degraded products in the tissue environment are still unknown, as both can produce cytotoxic effects and promote unwanted wound reactions. In this study, we develop biodegradable fibrous biomaterials embedded with metal particles that have an immune activation functions. Initially, biodegradable zinc (Zn) nanoparticles were modified with zein (G), a protein derived from corn. The zein-coated zinc particles (Z-G) were then embedded in polycaprolactone (P) fibers at different weight ratios to create fibrous biomaterials via electrospinning, which were subsequently analyzed for potential wound healing applications. We performed multimodal evaluations of the fibrous scaffolds, examining physicochemical properties such as fiber morphology, mechanical strength, hydrophilicity, degradation, and release of zinc ions (Zn2+), as well as biological properties, including in vitro cell culture studies. We provide evidence that the integration of 2.4 wt % of Z-G particles in polycaprolactone (PCL) nanofibrous scaffolds improved its physicochemical and biological functions. The in vitro cellular response of the scaffolds was evaluated using a series of cytotoxicity assays and immunocytochemistry analyses with three different cell types: mouse-derived fibroblast cell lines (NIH/3T3), human dermal fibroblasts (HDFn), and human umbilical vein endothelial cells (HUVECs). The composite fibrous scaffold exhibited robust activation and proliferation of NIH/3T3 and HDFn cells, along with a significant angiogenic potential in HUVECs. Immunocytochemistry confirmed elevated expression of vimentin and α-smooth muscle actin (α-SMA), suggesting that NIH/3T3 and Haden cells were highly differentiated into myofibroblasts. Additionally, the increased expression of CD31 and VE-cadherin in HUVECs suggests that the scaffold supports tube formation, thereby enhancing neovascularization and promoting an effective immune response. Overall, our findings demonstrate the regenerative potential of the self-enhanced Zn hemostatic bioscaffolds, which deliver both Zn2+ ions and zein proteins to nourish cells. This capability not only modulates cellular activities but also contributes to tissue repair and remodeling, making the scaffolds suitable for wound repair and various bioengineering applications.