RESUMEN

Hydrogel-based wound management systems represent a promising avenue in tissue engineering for restoring and preserving the normal functionality of damaged tissues. Incorporating active components into hydrogel matrices enhances their suitability for biomedical applications. In this study, we investigated the integration of l-proline, a nonessential imino acid with largely unexplored roles in living systems, into alginate dialdehyde-gelatin hydrogel for wound healing purposes. Physicochemical properties of the resulting hydrogel film, termed ADAGLP, were meticulously evaluated, including wound healing efficacy in vitro and anti-biofilm activity against Gram-positive and Gram-negative microorganisms. Fourier-transform infrared spectroscopy (FTIR) analysis provided insights into the interaction between l-proline and ADAG. Films incorporating 0.5% l-proline were selected for comprehensive investigation. Comparative analysis revealed prolonged gelation time and increased water holding capacity of ADAGLP compared to ADAG films. Moreover, ADAGLP exhibited a significantly higher degradation rate (69.5 ± 3.2%) compared to ADAG (35.2 ± 1.6%). Remarkably, ADAGLP demonstrated cyto-compatibility, non-toxicity, and facilitated migration to the scratch area in vitro conditions. Notably, it exhibited potent anti-biofilm properties. Our findings suggest that ADAGLP hydrogel holds promise as a biomaterial for wound care, offering prolonged drug delivery and maintaining optimal moisture levels in wound areas. The incorporation of l-proline in the wound microenvironment may contribute to enhanced tissue remodeling, by inhibiting biofilm formation, further highlighting the potential of this hydrogel system in wound healing applications.

Asunto(s)

Alginatos , Gelatina , Prolina , Cicatrización de Heridas , Alginatos/química , Cicatrización de Heridas/efectos de los fármacos , Gelatina/química , Prolina/química , Hidrogeles/química , Humanos , Biopelículas/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/administración & dosificación , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Animales , Ratones , Metilgalactósidos

RESUMEN

Injectable hydrogels fabricated from natural polymers have attracted increasing attentions for their potential in biomedical application owing to the biocompatibility and biodegradability. A new class of natural polymer based self-healing hydrogel is constructed through dynamic covalent bonds. The injectable self-healing hydrogels are fabricated by introducing alginate aldehyde to form Schiff base bonds with the chitin nanofibers. These hydrogels demonstrate excellent self-healing properties, injectability, and pH-responsive sol-gel transition behaviors. As a result, they can serve as carriers to allow an effective encapsulation of doxorubicin (DOX) for drug delivery. Furthermore, these hydrogels exhibit excellent biocompatibility and degradability in vitro and in vivo. The sustained release of DOX from the hydrogels effectively suppresses tumor growth in animal models without causing significant systemic toxicity, suggesting their potential application in anti-tumor therapies.

Asunto(s)

Alginatos , Antineoplásicos , Quitina , Doxorrubicina , Hidrogeles , Nanofibras , Quitina/química , Quitina/análogos & derivados , Alginatos/química , Nanofibras/química , Animales , Doxorrubicina/química , Doxorrubicina/farmacología , Hidrogeles/química , Antineoplásicos/farmacología , Antineoplásicos/química , Humanos , Ratones , Sistemas de Liberación de Medicamentos , Portadores de Fármacos/química , Liberación de Fármacos , Materiales Biocompatibles/química , Inyecciones , Línea Celular Tumoral

RESUMEN

In this study, we developed polydopamine (PDA)-functionalized alginate dialdehyde-gelatine (ADA-GEL) scaffolds for subchondral bone regeneration. These polymeric scaffolds were then coated with ß-Lactoglobulin (ß-LG) at concentrations of 1 mg/ml and 2 mg/ml. Morphological analysis indicated a homogeneous coating of the ß-LG layer on the surface of network-like scaffolds. The ß-LG-coated scaffolds exhibited improved swelling capacity as a function of the ß-LG concentration. Compared to ADA-GEL/PDA scaffolds, the ß-LG-coated scaffolds demonstrated delayed degradation and enhanced biomineralization. Here, a lower concentration of ß-LG showed long-lasting stability and superior biomimetic hydroxyapatite mineralization. According to the theoretical findings, the single-state, representing the low concentration of ß-LG, exhibited a homogeneous distribution on the surface of the PDA, while the dimer-state (high concentration) displayed a high likelihood of uncontrolled interactions. ß-LG-coated ADA-GEL/PDA scaffolds with a lower concentration of ß-LG provided a biocompatible substrate that supported adhesion, proliferation, and alkaline phosphatase (ALP) secretion of sheep bone marrow mesenchymal stem cells, as well as increased expression of osteopontin (SPP1) and collagen type 1 (COL1A1) in human osteoblasts. These findings indicate the potential of protein-coated scaffolds for subchondral bone tissue regeneration. STATEMENT OF SIGNIFICANCE: This study addresses a crucial aspect of osteochondral defect repair, emphasizing the pivotal role of subchondral bone regeneration. The development of polydopamine-functionalized alginate dialdehyde-gelatine (ADA-GEL) scaffolds, coated with ß-Lactoglobulin (ß-LG), represents a novel approach to potentially enhance subchondral bone repair. ß-LG, a milk protein rich in essential amino acids and bioactive peptides, is investigated for its potential to promote subchondral bone regeneration. This research explores computationally and experimentally the influence of protein concentration on the ordered or irregular deposition, unravelling the interplay between coating structure, scaffold properties, and in-vitro performance. This work contributes to advancing ordered protein coating strategies for subchondral bone regeneration, providing a biocompatible solution with potential implications for supporting subsequent cartilage repair.

Asunto(s)

Alginatos , Regeneración Ósea , Materiales Biocompatibles Revestidos , Gelatina , Indoles , Lactoglobulinas , Polímeros , Andamios del Tejido , Alginatos/química , Alginatos/farmacología , Indoles/química , Indoles/farmacología , Andamios del Tejido/química , Animales , Polímeros/química , Polímeros/farmacología , Regeneración Ósea/efectos de los fármacos , Gelatina/química , Ovinos , Lactoglobulinas/química , Lactoglobulinas/farmacología , Materiales Biocompatibles Revestidos/farmacología , Materiales Biocompatibles Revestidos/química , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Aldehídos/química , Proliferación Celular/efectos de los fármacos

RESUMEN

Three-dimensional (3D) printing allows precise manufacturing of bone scaffolds for patient-specific applications and is one of the most recently developed and implemented technologies. In this study, bilayer and multimaterial alginate dialdehyde-gelatin (ADA-GEL) scaffolds incorporating polydopamine (PDA)/SiO2-CaO nanoparticle complexes were 3D printed using a pneumatic extrusion-based 3D printing technology and further modified on the surface with bovine serum albumin (BSA) for application in bone regeneration. The morphology, chemistry, and in vitro bioactivity of PDA/SiO2-CaO nanoparticle complexes were characterized (n = 3) and compared with those of mesoporous SiO2-CaO nanoparticles. Successful deposition of the PDA layer on the surface of the SiO2-CaO nanoparticles allowed better dispersion in a liquid medium and showed enhanced bioactivity. Rheological studies (n = 3) of ADA-GEL inks consisting of PDA/SiO2-CaO nanoparticle complexes showed results that may indicate better injectability and printability behavior compared to ADA-GEL inks incorporating unmodified nanoparticles. Microscopic observations of 3D printed scaffolds revealed that PDA/SiO2-CaO nanoparticle complexes introduced additional topography onto the surface of 3D printed scaffolds. Additionally, the modified scaffolds were mechanically stable and elastic, closely mimicking the properties of natural bone. Furthermore, protein-coated bilayer scaffolds displayed controllable absorption and biodegradation, enhanced bioactivity, MC3T3-E1 cell adhesion, proliferation, and higher alkaline phosphatase (ALP) activity (n = 3) compared to unmodified scaffolds. Consequently, the present results confirm that ADA-GEL scaffolds incorporating PDA/SiO2-CaO nanoparticle complexes modified with BSA offer a promising approach for bone regeneration applications.

Asunto(s)

Indoles , Nanopartículas , Polímeros , Andamios del Tejido , Humanos , Andamios del Tejido/química , Alginatos/química , Gelatina/química , Albúmina Sérica Bovina , Dióxido de Silicio , Regeneración Ósea , Impresión Tridimensional , Ingeniería de Tejidos/métodos , Osteogénesis

RESUMEN

In this study, electrospun zein/alginate dialdehyde (AD) nanofibers were prepared by green crosslinking. The degree of crosslinking could reach 50.72 %, and the diameter of electrospun fibers ranged from 446.2 to 541.8 nm. The generation of AD and the bonding of crosslinking were further confirmed by the changes on characteristic peaks and conformational ratios in the infrared spectroscopy and secondary structure analysis. High concentrations of AD led to improved thermal stabilities, mechanical properties, and hydrophobicity. And the highly crosslinked nanofibers (Z-8) owned the highest elastic modulus (24.92 MPa), tensile strength (0.28 MPa), and elongation at break (8.14 %) among five samples. Moreover, Z-8 possessed a high swelling ratio of 5.45 g/g, and a low weight loss of 6.09 %. The samples could encapsulate curcumin efficiently and show controllable release behaviors based on different AD addition. And the oxidation resistance of nanofibers gradually improved, consistent with the release performances. This study indicated AD crosslinking favored the preparation and application of zein nanofibers, and the oxidized polysaccharide acted as the green crosslinking agent, which provided reference value for the application of polysaccharides in food-related electrospun materials.

Asunto(s)

Curcumina , Nanofibras , Zeína , Zeína/química , Alginatos , Nanofibras/química , Resistencia a la Tracción

RESUMEN

The objective of this study was to develop fluorescence nanofibrous polyvinyl alcohol/oxidized sodium alginate (PVA-OSA) incorporated with carbon dots (CDs) through Schiff-base interaction. The carbon dots used in this study were derived from the polyphenol-enriched extract of pomegranate peel, as established in previous work, as the reinforcing and antioxidant agent to enhance the physicochemical and biological properties of the nanofibers were used. The fabricated nanofibers were characterized using FE-SEM, FT-IR, XRD, and DSC analysis. The FE-SEM results revealed that an increase in the number of CDs in the nanofibers led to a decrease in diameter (809.6 ± 77.1 nm to 273.16 ± 41.1 nm). Furthermore, surface modification caused a significant reduction in the amount of surface roughness of the nanofibers. Incorporating CDs not only reduced the scaffold diameter but also improved its mechanical properties and promoted the growth of fibroblast cells. The ultimate tensile strength of scaffolds with and without CDs was 2.15 ± 0.02 MPa and 1.53 ± 0.74 MPa respectively. The influence of CDs amount on the properties of nanofibers showed that the swelling capacity and degradability of nanofibers can be adjusted by changing the range of CDs. Apart from the aforementioned benefits of incorporating CDs in improving nanofiber properties, their exceptional antioxidant properties can be harnessed for protecting nanofibers against oxidation and as a healing agent in wound dressings.

Asunto(s)

Antioxidantes , Nanofibras , Alcohol Polivinílico , Espectroscopía Infrarroja por Transformada de Fourier , Alginatos , Carbono

RESUMEN

The central nervous system has limited regeneration potential. The multipotency of adipose-derived mesenchymal stem cells (ADMSC) makes them an ideal autologous cell source for the regeneration of neural tissues. However, the likelihood of their differentiation into unwanted cell lineages when transplanted into a hostile injury environment is a serious disadvantage. Transplanting predifferentiated cells via an injectable carrier may aid in site-specific delivery for better survival of cells. Here, we focus on identifying an appropriate injectable hydrogel system that favors stem/progenitor cell attachment and differentiation for neural tissue engineering. An injectable composition of the hydrogel, derived from alginate dialdehyde (ADA) and gelatin, was formulated for this purpose. This hydrogel promoted proliferation/differentiation of ADMSCs to neural progenitors, visualized from the generation of prominent neurospheres and stage-specific expression of a neural progenitor marker (nestin, day 4), an intermittent neuronal marker (ß-III tub, day 5), and a mature neuronal marker (MAP-2, day 8) with neural branching and networking (>85%). The differentiated cells also expressed the functional marker synaptophysin. There was no negative impact on stem/progenitor cell survival (>95%) or differentiation (∼90%) as compared to two-dimensional (2D) culture. Addition of appropriate quantities of asiatic acid specific for neural niche supported cell growth and differentiation without affecting cell survival (>90%) and improved neural branching and elongation. Optimized interconnected porous hydrogel niche exhibited rapid gelation (3 min) and self-healing properties mimicking native neural tissue. Both ADA-gelatin hydrogel by itself and that incorporated with asiatic acid were found to support stem/neural progenitor cell growth and differentiation and have potential applications as antioxidants and growth promoters upon release at the cell transplantation site. In short, the matrix itself or incorporated with phytomoieties could serve as a potential minimally invasive injectable cell delivery vehicle for cell-based therapies of neural diseases.

Asunto(s)

Células Madre Mesenquimatosas , Células-Madre Neurales , Ratas , Animales , Hidrogeles/metabolismo , Ingeniería de Tejidos/métodos , Gelatina/farmacología , Gelatina/metabolismo , Alginatos , Células Cultivadas , Células Madre Mesenquimatosas/metabolismo

RESUMEN

Alginate dialdehyde and l-lysine-functionalized alginate dialdehyde were prepared to provide active aldehyde and l-lysine sites along the alginate backbone, respectively. Different concentrations of substrates and the reduction agent were added, and their influence on the degree of l-lysine substitution was evaluated. An amination reduction reaction (with l-lysine) was conducted on alginate dialdehyde with a 31% degree of oxidation. The NMR confirmed the presence of l-lysine functionality with the degree of substitution of 20%. The structural change of the polymer was observed via FTIR spectroscopy, confirming the formation of Schiff base covalent linkage after the crosslinking. The additional l-lysine sites on functionalized alginate dialdehyde provide more crosslinking sites on the hydrogel, which leads to a higher modulus storage rate than in the original alginate dialdehyde. This results in dynamic covalent bonds, which are attributed to the alginate derivative-gelatin hydrogels with shear-thinning and self-healing properties. The results suggested that the concentration and stoichiometric ratio of alginate dialdehyde, l-lysine-functionalized alginate dialdehyde, and gelatin play a fundamental role in the hydrogel's mechanical properties.

RESUMEN

Carbon-decorated ferrite nanodots (MNF@Cs) have been enhanced with superparamagnetism and higher fluorescence quantum yield by encapsulation with an alginate derivative to create a cost-effective and less toxic multimodal contrast agent for replacing the conventional heavy metal Gd-containing contrast agent used in MR imaging. The novel surface-engineered particles (MNF@C-OSAs), devoid of labels, can simultaneously provide both longitudinal and transverse relaxation-based magnetic resonance imaging (MRI) and fluorescence emission. According to the findings of in vitro studies, the calculated molar relaxivities and the molar radiant efficiencies are indicative of the multimodal efficacy of MNF@C-OSA as compared with MNF@C particles and conventional contrast agents used in medical imaging. MNF@C-OSAs were shown to be significantly biocompatible and negligibly toxic when assessed against A549 cells and zebrafish embryos, indicating their potential for use as theranostic agents.

RESUMEN

This study utilized extrusion-based 3D printing technology to fabricate calcium-cross-linked alginate dialdehyde-gelatin scaffolds for bone regeneration. The surface of polymeric constructs was modified with mussel-derived polydopamine (PDA) in order to induce biomineralization, increase hydrophilicity, and enhance cell interactions. Microscopic observations revealed that the PDA layer homogeneously coated the surface and did not appear to induce any distinct change in the microstructure of the scaffolds. The PDA-functionalized scaffolds were more mechanically stable (compression strength of 0.69 ± 0.02 MPa) and hydrophilic (contact angle of 26) than non-modified scaffolds. PDA-decorated ADA-GEL scaffolds demonstrated greater durability. As result of the 18-days immersion in simulated body fluid solution, the PDA-coated scaffolds showed satisfactory biomineralization. Based on theoretical energy analysis, it was shown that the scaffolds coated with PDA interact spontaneously with osteocalcin and osteomodulin (binding energy values of -35.95 kJ mol-1 and -46.39 kJ mol-1, respectively), resulting in the formation of a protein layer on the surface, suggesting applications in bone repair. PDA-coated ADA-GEL scaffolds are capable of supporting osteosarcoma MG-63 cell adhesion, viability (140.18% after 7 days), and proliferation. In addition to increased alkaline phosphatase secretion, osteoimage intensity also increased, indicating that the scaffolds could potentially induce bone regeneration. As a consequence, the present results confirm that 3D printed PDA-coated scaffolds constitute an intriguing novel approach for bone tissue engineering.

RESUMEN

Fibrin hydrogels are one of the most popular scaffolds used in tissue engineering due to their excellent biological properties. Special attention should be paid to the use of human plasma-derived fibrin hydrogels as a 3D scaffold in the production of autologous skin grafts, skeletal muscle regeneration and bone tissue repair. However, mechanical weakness and rapid degradation, which causes plasma-derived fibrin matrices to shrink significantly, prompted us to improve their stability. In our study, plasma-derived fibrin was chemically bonded to oxidized alginate (alginate di-aldehyde, ADA) at 10%, 20%, 50% and 80% oxidation, by Schiff base formation, to produce natural hydrogels for tissue engineering applications. First, gelling time studies showed that the degree of ADA oxidation inhibits fibrin polymerization, which we associate with fiber increment and decreased fiber density; moreover, the storage modulus increased when increasing the final volume of CaCl2 (1% w/v) from 80 µL to 200 µL per milliliter of hydrogel. The contraction was similar in matrices with and without human primary fibroblasts (hFBs). In addition, proliferation studies with encapsulated hFBs showed an increment in cell viability in hydrogels with ADA at 10% oxidation at days 1 and 3 with 80 µL of CaCl2; by increasing this compound (CaCl2), the proliferation does not significantly increase until day 7. In the presence of 10% alginate oxidation, the proliferation results are similar to the control, in contrast to the sample with 20% oxidation whose proliferation decreases. Finally, the viability studies showed that the hFB morphology was maintained regardless of the degree of oxidation used; however, the quantity of CaCl2 influences the spread of the hFBs.

Asunto(s)

Aldehídos , Alginatos , Hidrogeles , Aldehídos/química , Alginatos/química , Cloruro de Calcio/farmacología , Fibrina , Humanos , Hidrogeles/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química

RESUMEN

This study used methylcellulose (MC) to improve the printability of the alginate dialdehyde-gelatin (ADA-GEL) based bioink. The printability as well as the capability to maintain shape fidelity of ADA-GEL could be enhanced by the addition of 9% (w/v) MC. Moreover, the properties of the ink crosslinked with Ca2+ and Ba2+ were investigated. The samples crosslinked with Ba2+ were more stable and stiffer than the Ca2+ crosslinked samples. However, both Ca2+ and Ba2+ crosslinked samples exhibited a similar trend of MC release during incubation under cell culture conditions. The toxicity test indicated that both samples (crosslinked with Ca2+ and Ba2+) exhibited no toxic potential. The fabrication of cell-laden constructs using the developed bioinks was evaluated. The viability of ST2 cells in Ba2+ crosslinked samples increased while for Ca2+ crosslinked samples, a decreased viability was observed over the incubation time. After 21 days, cell spreading in the hydrogels crosslinked with Ba2+ occurred. However, a certain degree of cell damage was observed after incorporating the cells in the high viscosity bioink.

Asunto(s)

Bioimpresión , Gelatina , Alginatos , Supervivencia Celular , Hidrogeles , Metilcelulosa , Impresión Tridimensional , Andamios del Tejido

RESUMEN

Organic-inorganic hybrid materials overcome drawbacks associated with alginate hydrogels. In this work, covalently coupled silica-alginate hybrids were prepared by Schiff base formation and sol-gel reaction using alginate dialdehyde (ADA), (3-Aminopropyl) triethoxysilane (APTES), and APTES/tetraethylorthosilicate (TEOS) precursors. The influence of the polysaccharide/inorganic ratio, the nature of the inorganic precursor and the ionic crosslinking ability are studied. Prepared hybrids were characterized by FT-IR, 13C and 29Si NMR spectroscopies, SEM, and rheology. For ADA/APTES hybrids, at higher ADA content, Schiff base formation is predominant, but at lower ADA content, the sol-gel reaction is prevalent. However, the progress of the sol-gel reactions for ADA/(APTES+TEOS), is favored with higher ADA compositions. Introducing a posterior ionic crosslinking treatment was possible, increasing the moduli in ADA/(APTES+TEOS) hybrids from 86,207 Pa for 1.5 ADA/Si to 362,171 Pa for 1.5 ADA/Si-Ca. In-situ ADA-Silica hybrid hydrogels containing both ionic and covalent crosslinking can be successfully synthesized with the proposed method. CARBPOL-D-21-01042.

RESUMEN

A hydrogel system based on oxidized alginate covalently crosslinked with gelatin (ADA-GEL) has been utilized for different biofabrication approaches to design constructs, in which cell growth, proliferation and migration have been observed. However, cell-bioink interactions are not completely understood and the potential effects of free aldehyde groups on the living cells have not been investigated. In this study, alginate, ADA and ADA-GEL were characterized via FTIR and NMR, and their effect on cell viability was investigated. In the tested cell lines, there was a concentration-dependent effect of oxidation degree on cell viability, with the strongest cytotoxicity observed after 72 h of culture. Subsequently, primary human cells, namely fibroblasts and endothelial cells (ECs) were grown in ADA and ADA-GEL hydrogels to investigate the molecular effects of oxidized material. In ADA, an extremely strong ROS generation resulting in a rapid depletion of cellular thiols was observed in ECs, leading to rapid necrotic cell death. In contrast, less pronounced cytotoxic effects of ADA were noted on human fibroblasts. Human fibroblasts had higher cellular thiol content than primary ECs and entered apoptosis under strong oxidative stress. The presence of gelatin in the hydrogel improved the primary cell survival, likely by reducing the oxidative stress via binding to the CHO groups. Consequently, ADA-GEL was better tolerated than ADA alone. Fibroblasts were able to survive the oxidative stress in ADA-GEL and re-entered the proliferative phase. To the best of our knowledge, this is the first report that shows in detail the relationship between oxidative stress-induced intracellular processes and alginate di-aldehyde-based bioinks.

Asunto(s)

Alginatos/química , Materiales Biocompatibles/química , Células Endoteliales/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Gelatina/química , Estrés Oxidativo/efectos de los fármacos , Alginatos/toxicidad , Animales , Materiales Biocompatibles/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Células Endoteliales/citología , Fibroblastos/citología , Gelatina/toxicidad , Humanos , Ratones , Células 3T3 NIH , Andamios del Tejido/química

RESUMEN

INTRODUCTION: Development of a tissue-engineered construct for hepatic regeneration remains a challenging task due to the lack of an optimum environment that support the growth of hepatocytes. Hydrogel systems possess many similarities with tissues and have the potential to provide the microenvironment essential for the cells to grow, proliferate, and remain functionally active. METHODS: In this work, fibrin (FIB) incorporated injectable alginate dialdehyde (ADA) - gelatin (G) hydrogel was explored as a matrix for liver tissue engineering. ADA was prepared by periodate oxidation of sodium alginate. An injectable formulation of ADA-G-FIB hydrogel was prepared and characterized by FTIR spectroscopy, Scanning Electron Microscopy, and Micro-Computed Tomography. HepG2 cells were cultured on the hydrogel system; cellular growth and functions were analyzed using various functional markers. RESULTS: FTIR spectra of ADA-G-FIB depicted the formation of Schiff's base at 1608.53 cm-1 with a gelation time of 3 min. ADA-G-FIB depicted a 3D surface topography with a pore size in the range of 100-200 µm. The non-cytotoxic nature of the scaffold was demonstrated using L929 cells and more than 80 % cell viability was observed. Functional analysis of cultured HepG2 cells demonstrated ICG uptake, albumin synthesis, CYP-P450 expression, and ammonia clearance. CONCLUSION: ADA-G-FIB hydrogel can be used as an effective 3D scaffold system for liver tissue engineering.

Asunto(s)

Alginatos/química , Fibrina/análogos & derivados , Hidrogeles/síntesis química , Regeneración Hepática , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Aldehídos/química , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Gelatina/química , Células Hep G2 , Humanos , Hidrogeles/efectos adversos , Ratones , Andamios del Tejido/efectos adversos

RESUMEN

Fish-derived gelatin (FG), a raw material for edible films, has recently been spotlighted as an alternative source of mammalian gelatin. However, its low stability under moisture conditions and weak mechanical properties limit its application. In this study, a water-stable and mechanically robust FG film was prepared using alginate dialdehyde (ADA) as an eco-friendly crosslinking agent. The crosslinking process of FG with ADA was easily recognized by the change in the color of the FG/ADA composite film, and the browning index of the FG/ADA film could be correlated well with the actual crosslinking degree. The mechanical strength and Young's modulus of the FG/ADA composite film increased significantly with an increase in the content of the ADA crosslinker. In the case of FG/ADA10, the tensile strength and Young's modulus increased by 400 and 600 %, respectively, compared to those of FG. Remarkably, the FG-ADA crosslinking process greatly decreased the vulnerability of FG in moisture environments. Consequently, the FG/ADA10 film remained stable for 30 days under wet environment. In addition, the FG-ADA crosslinking process could enhance the antioxidative capacity of the FG/ADA edible film. According to this study, FG/ADA composite films fabricated in an effective manner using polymers derived from aquatic species like gelatin from fish and ADA from algae could have practical applications in the edible film-based packaging industry.

RESUMEN

As cartilage is one of the few tissues in the human body that is not vascularized, the body has very limited capabilities to repair cartilage defects. Hence, novel condro-instructive biomaterials facilitating cartilage formation by implanted chondrocytes are required. In this work, an oxidized alginate-gelatin hydrogel system, alginate-di-aldehyde (ADA) and gelatin (GEL), was used to fabricate 3D printed grid-like structures for cartilage tissue engineering. Enzymatic and ionic crosslinking techniques using microbial transglutaminase (mTG) and divalent ions (CaCl2) were combined to ensure long-term stability of the 3D printed structures. Human nasoseptal chondrocytes were embedded in ADA-GEL prior to 3D printing. Cell viability, proliferation, and metabolic activity were analyzed after 7 and 14 days. The influence of the enzymatic crosslinking and the 3D printing process on the primary human chondrocytes were investigated. It was found that neither the 3D printing process nor the crosslinking by mTG impaired chondrocyte viability. The formation of the main cartilage-specific extracellular matrix components collagen type II and cartilage proteoglycans was shown by immunohistochemical staining. The combination of enzymatic and ionic crosslinking for the 3D printing of ADA-GEL hydrogels is therefore a promising approach for the 3D cultivation of primary human chondrocytes for cartilage tissue engineering.

Asunto(s)

Bioimpresión , Gelatina , Alginatos , Cartílago , Condrocitos , Humanos , Hidrogeles , Impresión Tridimensional , Ingeniería de Tejidos , Andamios del Tejido

RESUMEN

We report a new robust and green facile platform for nonoxidizing chemical grafting to simultaneously improve antifouling and antibacterial properties of thin film composite (TFC) polyamide (PA) reverse osmosis (RO) membranes. In this work, alginate dialdehyde (ADA) was used as a green platform to graft chlorhexidine (CH), a nonoxidizing chemical, on TFC-RO membrane surface. A synergistic effect due to ADA and CH grafting was revealed. The modified membrane surfaces were characterized using XPS, FT-IR, AFM, SEM-EDS, contact angle, and zeta potential analysis. A simple two-step Schiff base reaction was performed. Improved salt rejection performances were observed for the grafted PA membranes at the expense of negligible flux drop for the CH-ADA-PA membranes (38 to 42 L m-2 h-1) compared with the pristine PA membrane (45 L m-2 h-1). All the CH-ADA-PA membranes had excellent antibacterial activity against E. coli along with a highly superior resistance to the formation of biofilms. Organic fouling behaviors with a protein (bovine serum albumin, BSA) and a surfactant (dodecyl trimethylammonium bromide, DTAB) were investigated as typical foulants for the grafted PA membranes. The results indicated that the CH-ADA-PA membranes showed the best antifouling performance followed by the ADA-PA membranes, the pristine membrane being the most inferior. Hence, these results pave the way for a new robust and green bioinspired route for practical application in RO membrane fouling control.

Asunto(s)

Alginatos/química , Antibacterianos/química , Clorhexidina/química , Materiales Biocompatibles Revestidos/química , Nylons/química , Aldehídos/química , Biopelículas , Incrustaciones Biológicas/prevención & control , Escherichia coli , Filtración , Tecnología Química Verde , Membranas Artificiales , Ósmosis , Compuestos de Amonio Cuaternario/química , Albúmina Sérica Bovina/química , Propiedades de Superficie , Purificación del Agua

RESUMEN

Electrospinning of pure alginate or derivatives has always been a pursuing goal in biological fields in recent years owing to its fascinating biological characteristics and biomimetic structures. Yet it is still a severe challenge in view of its insufficient entanglements and strong electrostatic repulsions. Herein, alginate dialdehyde (ADA) with improved and adjustable chain flexibility was prepared via periodate-oxidation. Chain flexibility, concentration, ethanol and crosslinkers played key roles in electrospinning proved by persistence length (lp), the number of entanglement points (ne) and fiber morphology. Finally, insoluble ADA corsslinked nanofiber membranes were obtained, which exhibited excellent mechanical properties and adjustable degradability. Specially, biocompatibility assays confirmed that the preparing membranes were noncytotoxic, and could promote cell attachment and proliferation. Therefore, under the guidance of the relationship between chain flexibility and electrospinnability, pure alginate-based nanofiber membranes are expected to become promising scaffolds for biomedical applications, particularly for wound healing which demanding appropriate degradation.

Asunto(s)

Alginatos/química , Materiales Biocompatibles/química , Nanofibras/química , Células 3T3 , Animales , Ratones , Ingeniería de Tejidos/métodos , Andamios del Tejido

RESUMEN

Compounds having antimicrobial activity were synthesized from sodium alginate, the main constituent of brown algae. Sodium alginate was oxidized with sodium periodate to get alginate dialdehyde (ADA). FTIR spectrum of the ADA gave very small peak characteristic for aldehyde groups at 1720 cm-1, indicating that the aldehyde group is masked somehow. It may be hydrated, involving at hemiacetal formation or hemialdol, similar to cellulose dialdehyde. Two methods were used for the condensation of ADA with o-phenylenediamine analogs to obtain the final products. The first method was stirring at room temperature and the second method was heating in microwave. The microwave method gave higher yield and shorter reaction time than the other method. The condensation reaction is considered as a shiff-base formation and the proposed mechanism was suggested. The condensation products were characterized by FTIR and UV spectra. The antimicrobial potency for five of these products in addition to the used alginate and to the precursor amines was evaluated against four pathogenic fungi and six pathogenic bacteria species.

Asunto(s)

Alginatos/farmacología , Antibacterianos/farmacología , Antifúngicos/farmacología , Hongos/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Alginatos/síntesis química , Alginatos/química , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Conformación de Carbohidratos , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Microondas , Relación Estructura-Actividad