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Electrospun membranes are compact structures with small pore sizes that hinder cell infiltration, resulting in membranes with cells attached only to the external surface rather than throughout the entire volume. Thus, there is a need to increase the pore size of electrospun membranes maintaining their structural similarity to the extracellular matrix. In this work, we used glucose crystals embedded in polyethylene oxide (PEO) fibers to create large pores in poly(lactic acid) (PLA) electrospun membranes to allow for cellular infiltration. The PEO fibers containing glucose crystals of different sizes (>50, 50-100 and 100-150 µm) and in varying concentrations (10, 15 and 20 %) were co-electrospun with PLA fibers and subsequently leached out using distilled water. PLA fibrous membranes without glucose crystals were also produced as controls. The membranes were examined for their morphology, mechanical properties, and potential to support the proliferation of fibroblasts. In addition, the immune response to the membranes was evaluated using monocyte-derived macrophages. The glucose crystals were uniformly distributed in the PLA membranes and their removal created open pores without collapsing the structure. Although a reduced Young's modulus was observed for membranes produced using higher glucose crystal concentrations and larger crystal sizes, the structural integrity remained intact, and the values are still suitable for tissue engineering. In vitro results showed that the scaffolds supported the adhesion and proliferation of fibroblasts and the pores created in the PLAmembranes were large enough for fibroblasts infiltration and colonization of the entire scaffold without inducing an inflammatory response.

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Large bone defect repair is a striking challenge in orthopedics. Currently, inorganic-organic composite scaffolds are considered as a promising approach to these bone regeneration. Silicon ions (Si4+) are bioactive and beneficial to bone regeneration and Si4+-containing inorganic mesoporous silica (MS) can effectively load drugs for bone repair. To better control the release of drug, we prepared biodegradable MS/PLGA (MP) microspheres. MP loaded organic silk fibroin/carboxymethyl chitosan/sodium alginate (MP/SF/CMCS/SA) composite scaffolds were further constructed by genipin and Ca2+ crosslinking. All MP/SF/CMCS/SA scaffolds had good swelling ability, degradation rate and high porosity. The incorporation of 1% MP significantly enhanced the compressive strength of composite scaffolds. Besides, MP loaded scaffold showed a sustained release of Si4+ and Ca2+. Moreover, the release rate of rhodamine (a model drug) of MP/SF/CMCS/SA scaffolds was obviously lower than that of MP. When culturing with rat bone marrow mesenchymal stem cells, scaffolds with 1% MP displayed good proliferation, adhesion and enhanced osteogenic differentiation ability. Based on the results above, the addition of 1% MP in SF/CMCS/SA scaffolds is a prospective way for drug release in bone regeneration and is promising for further in vivo bone repair applications.

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In this study, the effect of gamma ray irradiation on the granular and molecular structures of cassava starch was examined. Cassava starch was irradiated with various gamma ray doses of 25, 50, 75, and 100 kGy. After irradiation, the starch turned yellow, but its granular morphological characteristics remained intact. However, the inner part and the 'Maltese cross' of the starch granules irradiated with 100 kGy were broken, and its crystallinity decreased considerably. The pH reduction (from 5.6 to 3.7) and carboxyl content increase (up to 0.38 %) confirmed the formation of carboxyl groups on the irradiated starch chains. Gamma ray irradiation caused glycosidic bond cleavages, resulting in shortened amylose chains and debranched amylopectin chains containing terminal carboxyl groups. The irradiated starches with different molecular weights have high potential for use in food and non-food applications, for example, in bioplastics. Thermoplastic-irradiated starch (TPIS) materials, and their blends with poly(lactic acid) (PLA) were prepared via extrusion. Both TPIS and PLA/TPIS blends exhibited considerably increased melt flow index values compared with those from the unirradiated starch at approximate increases of 420-2260% and 2-55%, respectively. The improved melt flow ability and reduced viscosity are advantages for some plastic conversion processes such as injection molding.

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This work provides a straightforward strategy for synthesizing efficient bio-based flame-retardant plasticizers, offering promising prospects for flame-retardant flexible materials. Poly(lactic acid) (PLA) has garnered significant attention as an environmentally friendly polymer among numerous biodegradable materials. However, its high flammability and brittleness severely hinder its application in the field of electronics and electrical devices. To address these challenges, a bio-based flame-retardant plasticizer (EPDL) was designed and synthesized using renewable L-lactic acid, which significantly enhances the flexibility and flame retardancy of PLA. Incorporating 40 phr EPDL resulted in PLA achieving UL94 V-0 grade and a limiting oxygen index of 34.3 %, demonstrating excellent flame-retardant properties. Meanwhile, the peak of heat release rate and total heat release of PLA/EPDL blends exhibited a marked reduction by 23.1 % and 34.1 % compared to that of pristine PLA, respectively. The flame-retardant action mode of EPDL is the combination of gas phase and condensed phase action. Additionally, the introduction of 40 phr EPDL significantly enhanced the ductility of PLA, resulting in a substantial rise in the elongation at break of the PLA/EPDL to 181.8 %, which is approximately 52 times higher than neat PLA. Intriguingly, the crystallization performance of PLA was enhanced by the presence of EPDL.

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Sustainable poly (lactic acid) (PLA) with excellent strength, toughness, heat resistance, transparency, and biodegradability was achieved by uniaxial pre-stretching at 70 °C. The effect of pre-stretched ratio (PSR) on the microstructure and properties of the PLA was investigated. The undrawn PLA was brittle. However, after pre-stretching, the elongation at break was increased significantly. The maximum value of 161.2 % was obtained at pre-stretching ratio (PSR) of 1.0. With the increase of PSR, the modulus and strength were improved obviously (from 1601 MPa and 60.2 MPa for undrawn PLA to 2932 MPa and 106.3 MPa for the ps-PLA at PSR =3.0). Meanwhile, the heat resistance of PLA was improved obviously with the increase of PSR. For the ps-PLA3.0, there were almost no deformation and shrink at 140 °C. Interestingly, after pre-stretching, the PLA still maintained the good transparency and biodegradability. The brittleness for undrawn PLA was attributed to the network structure of cohesional entanglements. After pre-stretching, the destruction of the network structure and formation of the orientation, mesophase and oriented nanosized crystalline phase lead to the increased the toughness, strength and heat resistance without sacrificing the transparency and biodegradability. This work provides a significant guidance for the fabrication of PLA material with excellent comprehensive performance including strength, toughness, heat resistance, transparency, and biodegradability.

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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.

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Plasticized PLA plastic films are being increasingly used in, among others, packaging and agriculture sectors in an attempt to address the rapid growth of municipal waste. The present paper aims to review the recent progress and the state-of-the-art in the field of fully bio-renewable tough blends of PLA with green plasticizers aimed at developing flexible packaging films. The different classes of green substances, derived from completely bio-renewable resources, used as potential plasticizers for PLA resins are reviewed. The effectiveness of these additives for PLA plasticization is discussed by describing their effects on different properties of PLA. The performance of these blends is primarily determined by the solvent power, compatibility, efficiency, and permanence of plasticizer present in the PLA matrix of resulting films. The various chemical modification strategies employed to tailor the phase interactions, dispersion level and morphology, plasticization efficiency, and permanence, including functionalization, oligomerization, polymerization and self-crosslinking, grafting and copolymerization, and dynamic vulcanization are demonstrated. Sometimes a third component has also been added to the plasticized binary blends as compatibilizer to further promote dispersion and interfacial adhesion. The impact of chemical structure, size and molecular weight, chemical functionalities, polarity, concentration, topology as well as molecular architectures of the plasticizers on the plasticizer performance and the overall characteristics of resulting plasticized PLA materials is discussed. The morphological features and toughening mechanisms for PLA/plasticizer blends are also presented. The different green liquids employed show varying degree of plasticization. Some are more useful for semi-rigid applications, while some others can be used for very flexible products. There is an optimum level of plasticizer in PLA matrices above which the tensile ductility deteriorates. Esters-derivatives of bio-based plasticizers have been shown to be very promising additives for PLA modification. Some plasticizers impart additional functions such as antioxidation and antibacterial activity to the resulting PLA materials, or compatibilization in PLA-based blends. While the primary objective of plasticization is to boost the processability, flexibility, and toughness over wider practical conditions, the bio-degradability, permeability and long-term stability of microstructure (and thereby properties) of the plasticized films against light, weathering, thermal aging, and oxidation deserve further investigations.

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Bio-based multilayer films were prepared by using the innovative nanolayer coextrusion process to produce films with a number of alternating layers varying from 3 to 2049. For the first time, a semicrystalline polymer was confined by another semicrystalline polymer by nanolayering in order to develop high barrier polyamide (PA11)/polylactic acid (PLA) films without compromising thermal stability and mechanical behavior. This process allows the preparation of nanostratified films with thin layers (down to nanometric thicknesses) in which a confinement effect can be induced. The stratified structure has been investigated, and the layer thicknesses have been measured. Barrier properties were successfully correlated to the microstructure, as well as the thermal behavior, and mechanical properties. The layer continuity was fully achieved for most of the films, but some layer breakups have been observed on the film with the thinnest PLA layer (2049-layers film). Coextruding PLA with PA11 has induced an increase in PLA crystallinity (from 4 to 16%) along with an increase in thermal stability of the multilayer films without impacting PA11 properties. Gas barrier properties were driven by the PLA confined layers due to the microstructural rearrangement by increasing crystallinity, whereas water barrier properties were governed by the PA11 confining layers due to its lower water affinity. As a consequence, a decrease of water permeability (up to 11 times less permeable for the 6M film) but an increase of gas barrier properties (barrier improvement factor (BIF) of 66% for the 0M film for N2 and BIF of 36% for the 6M film for CO2 for instance) were evidenced as the layer number was increased. This study paves the way for the development of ecofriendly materials with outstanding barrier performances and highlights the importance of nonmiscible polymers adhesion at melt state and additives presence.

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Amid the current environmental crisis caused by plastic accumulation, one of the proposed solutions to manage this problem is using biodegradable polymers. However, the impact of adding biodegradable polymers to the well-established circular economy of recyclable polymers, such as HDPE, has not been fully considered. Therefore, there is a need to reconsider the way we consume, dispose of, and manage biodegradable polymers after use. This study evaluates the effect of varying the contents of a biodegradable polymer, taking poly(lactic acid) (PLA) as a model biodegradable polymer, on the thermal and mechanical properties of HDPE. The study highlights the importance of identifying and disposing of biodegradable polymers to avoid mixtures with HDPE, in order not to affect mechanical performance when considering reprocessing and a new life cycle of this conventional polymer.

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High-performance poly(lactic acid) (PLA) blend-based composites were fabricated with a poly(ether-block-amide) (PEBA) elastomer acting as the blend counterpart. It was confirmed that a compatibilizer (ADR) enhanced the interaction between PLA and PEBA. Carbon nanotubes (CNTs) and organoclay (30B) were added individually and simultaneously into the blend to produce bionanocomposites. Morphological results showed that CNTs were mainly dispersed in PEBA domains, whereas 30B was mainly localized at the interfacial region of PLA and PEBA phases. The selective localization of added CNTs and 30B led to significant modification of the properties of the compatibilized PLA/PEBA blend. The brittleness and flammability of PLA were evidently improved after forming the bionanocomposites. Differential scanning calorimetry results revealed that CNTs and 30B assisted the crystallization of both PLA and PEBA in the composites, with CNTs providing superior nucleation efficiency to 30B. Thermogravimetric analysis revealed the thermal stability enhancement of the blend after adding CNTs and/or 30B, with up to 16 °C increase at 20 wt% loss with inclusion of 2 phr 30B. Addition of CNTs and/or 30B improved the blend's anti-dripping performance during burning tests, and CNT exhibited better anti-dripping efficiency. Ductility of PLA was drastically improved after forming the compatibilized blend, and further improved with incorporation of CNTs and/or 30B (increased from 9 % for neat PLA to 252 % for the hybrid composite containing CNT/30B). The impact strength of 1 phr CNTs-added composite was about 3 times that of PLA. Rheological properties indicated the (pseudo)network formation of added filler(s), leading to a significant reduction in electrical resistivity, up to six orders of magnitude with addition of 3 phr CNTs.

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Biodegradable poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) triblock copolymer could potentially be used in bioplastic applications because it is more flexible than PLLA. However, investigations into modifying PLLA-PEG-PLLA with effective fillers are still required. In this work, bamboo biochar (BC) was used as an eco-friendly and cost-effective filler for the flexible PLLA-PEG-PLLA. The influences of BC addition on crystallization properties, thermal stability, hydrophilicity, and mechanical properties of the PLLA-PEG-PLLA were explored and compared to those of the PLLA. The PLLA-PEG-PLLA matrix and BC filler were found to have strong interfacial adhesion and good phase compatibility, while the PLLA/BC composites displayed weak interfacial adhesion and poor phase compatibility. For the PLLA-PEG-PLLA, the addition of BC induced a nucleation effect that was characterized by a decrease in the cold crystallization temperature from 76 to 71-75 °C and an increase in the crystallinity from 18.6 to 21.8-24.0%; however, this effect was not observed for the PLLA. When compared to pure PLLA-PEG-PLLA, the PLLA-PEG-PLLA/BC composites displayed greater thermal stability, tensile stress, and Young's modulus. Temperature at maximum decomposition rate (Td,max) of PLLA end-blocks increased from 315 to 319-342 °C. Ultimate tensile stress of PLLA-PEG-PLLA matrix improved from 14.5 to 16.2-22.6 MPa and Young's modulus increased from 220 to 280-340 MPa. Based on the findings, the crystallizability, thermal stability, and mechanical properties of the flexible PLLA-PEG-PLLA bioplastic were all enhanced by the use of BC as a multi-functional filler.

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Stereo-complexed poly(lactic acid) (SC-PLA) has unique stereo-complexed crystallites (SC) and homogeneous crystallites (HC), but the effect of this special crystalline property on the hydrolytic degradation of SC-PLA has not been researched. In this study, the hygrothermal aging behaviour of injection-molded SC-PLA and SC-PLA/microcrystalline cellulose (MCC) composites at different temperatures (25 °C and 60 °C) was investigated from micro- and macroscopic perspectives. The results demonstrated that the hydrolysis of SC-PLA was sequentially dominated by the amorphous region, the homogeneous crystalline region, the stereo-complexed crystalline region (three stages). The hydrolytic degradation of SC-PLA only completed the first stage after 4 weeks aging at 25 °C, while it was in the third stage after 4 weeks aging at 60 °C. On this basis, the accelerating effect of 10 wt% MCC on the hydrolysis process of SC-PLA at different stages was investigated. It was found that MCC shortened the hydrolysis time in the stereo-complexed crystalline region by reducing the rearrangement of amorphous structure to form SC and causing cracks and interfacial deterioration by water absorption-swelling-degradation. In addition, the thermal properties and impact strength of SC-PLA and SC-PLA/MCC composites decreased dramatically due to rapid hydrolytic degradation at 60 °C. Overall, the results of this study can provide theoretical basis for the application of SC-PLA and SC-PLA/MCC composites in hygrothermal environment.

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Temperature rising elution fractionation (TREF) approach was used to separate a biodegradable poly(lactic acid) (PLA) resin into ten fractions and completely establish the relationship between chain microstructure and properties. The main fractions were mainly eluted at 100, 110, 114, and 118 °C, and their mass percentages were 7.98 wt%, 44.83 wt%, 19.64 wt%, and 11.90 wt%, respectively. Through the use of successive self-nucleation/annealing (SSA) thermal fractionation, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and 13C-nuclear magnetic resonance spectroscopy (13C NMR), the intermolecular and intramolecular differences of PLA were further explored. Fractions eluted at 90, 110, 118, and 126 °C were also chosen to research the non-isothermal cold crystallization kinetics, and fractions eluted at 110, 118, and 126 °C were chosen to explore the non-isothermal crystallization kinetics in order to simulate the real process. The findings demonstrated that the Liu-Mo approach were more suited the non-isothermal crystallization and non-isothermal cold crystallization kinetics of PLA. As the elution temperature increased, so did the stereoregularity of the fractions, the crystallization rate, the crystallization capacity, and the lamellar thickness. These will lay a foundation for its basic research and industrial application.

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Antimicrobial wound dressings can aid wound healing by preventing bacterial infection. This is particularly true of electrospun ones, which have a porous structure and can be easily loaded with antimicrobial drugs. Here, Poly lactic acid (PLA), Silk Fibroin (SF) and antimicrobial agents of Silver nanoparticles (Ag NPs) and Silver oxide (Ag2O) to prepare the PLA/SF composites antimicrobial nanofiber membrane by electrospinning. The PLA with 30 % SF nanofiber membrane show the water vapor permeability (WVP) and the liquid absorption of 36 g·mm/(m2·d·kPa) and 1721 %. With the increasing of SF contents, the degradation rate and surface hydrophilicity of the nanofiber membrane increase significantly. The nanofiber membrane exhibited excellent antimicrobial activity against Pseudomonas aeruginosa (P. aeruginosa) with the inhibition circle reach at 18.2 mm. The resultant nanofiber membrane showed high cytosolic activity, good cytocompatibility and strong antimicrobial ability, which laid a theoretical foundation for the construction of a new PLA/SF composites antimicrobial fiber membrane.

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In this study, a twin-screw extruder was used to fabricate poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends and blend-based nanocomposites with carbon nanotube (CNT) or nanocarbon black (CB) as nanofillers. The fabricated samples were subsequently treated with supercritical carbon dioxide (scCO2) to fabricate the corresponding foams. Bi-phasic morphology and selective distribution of CNTs or CBs in the PBAT phase were observed in the blends/composites through scanning electron microscopy. After the scCO2 treatment, the selective foaming of the PBAT phase in the prepared blends/composites was confirmed. The cellular structure of PBAT phase in scCO2-treated blends is similar to the size/shape of PBAT domains in untreated blends or treated neat PBAT foam. The addition of CNTs or CBs in the blends led to a slight reduction in cell size of the foamed PBAT phase, demonstrating CNT/CB-induced cell nucleation. Differential scanning calorimetry (DSC) results showed that CNTs and CBs played as nucleating agents and increased the initial crystallization temperature up to 14 °C compared with neat PBAT for PBAT in different composites during cooling. The scCO2 treatment induced the bimodal stability of PBAT crystals in different samples, which melted mainly in two temperature regions in DSC studies. Thermogravimetric analyses revealed that compared with parent blends, the addition of CNTs or CBs increased the temperature at 80 wt.% loss (degradation of PBAT portion) up to 6 °C. The electrical resistivity decreased by more than six orders of magnitude for certain CNT- or CB-added composites compared with the parent blends. The hardness of the blends slightly increased after forming the corresponding composites and then declined after the scCO2 treatment.

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Poly(lactic-acid) (PLA) is a biodegradable polymer widely used as a packaging material. Its monomer, lactic acid, and its derivatives have been used in the food, cosmetic, and chemical industries. The accumulation of PLA residues leads to the development of green degrading methodologies, such as enzymatic degradation. This work evaluates the potential use of three cutinolytic enzymes codified in the Aspergillus nidulans genome to achieve this goal. The results are compared with those obtained with proteinase K from Tritirachium album, which has been reported as a PLA-hydrolyzing enzyme. The results show that all three cutinases act on the polymer, but ANCUT 1 releases the highest amount of lactic acid (25.86 mM). Different reaction conditions assayed later led to double the released lactic acid. A decrease in weight (45.96%) was also observed. The enzyme showed activity both on poly L lactic acid and on poly D lactic acid. Therefore, this cutinase offers the potential to rapidly degrade these package residues, and preliminary data show that this is feasible.

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The application of lignin as a filler for poly (lactic acid) (PLA) is limited by their poor interfacial adhesion. To address this challenge, lignin-graft-poly(lauryl methacrylate) (LG-g-PLMA) was first blended with poly (lactic acid), and then epoxidized soybean oil (ESO) was also added to prepare PLA/LG-g-PLMA/ESO composite, which was subsequently hot pressed to prepare the composite films. The effect of ESO as a plasticizer on the thermal, mechanical, and rheological properties, as well as the fracture surface morphology of the PLA/LG-g-PLMA composite films, were investigated. It was found that the compatibility and toughness of the composites were improved by the addition of ESO. The elongation at break of the composites with an ESO content of 5 phr was increased from 5.6% to 104.6%, and the tensile toughness was increased from 4.1 MJ/m3 to 44.7 MJ/m3, as compared with the PLA/LG-g-PLMA composite without ESO addition. The toughening effect of ESO on composites is generally attributed to the plasticization effect of ESO, and the interaction between the epoxy groups of ESO and the terminal carboxyl groups of PLA. Furthermore, PLA/LG-g-PLMA/ESO composite films exhibited excellent UV barrier properties and an overall migration value below the permitted limit (10 mg/dm2), indicating that the thus-prepared biocomposite films might potentially be applied to environmentally friendly food packaging.

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Polymer blends of poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) and high-density polyethylene (HDPE) with different blend ratios were prepared by a melt blending method. The thermal, morphological, mechanical, opacity, and biodegradation properties of the PLLA-PEG-PLLA/HDPE blends were investigated and compared to the PLLA/HDPE blends. The blending of HDPE improved the crystallization ability and thermal stability of the PLLA-PEG-PLLA; however, these properties were not improved for the PLLA. The morphology of the blended films showed that the PLLA-PEG-PLLA/HDPE blends had smaller dispersed phases compared to the PLLA/HDPE blends. The PLLA-PEG-PLLA/HDPE blends exhibited higher flexibility, lower opacity, and faster biodegradation and bioerosion in soil than the PLLA/HDPE blends. Therefore, these PLLA-PEG-PLLA/HDPE blends have a good potential for use as flexible and partially biodegradable materials.

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Enhancing food preservation and safety using environmentally friendly techniques is urgently needed. The aim of this study was to develop food packaging films using biodegradable poly-L-lactic acid (PLA) as biopolymer and carvacrol (CV) essential oil as an antioxidant/antibacterial agent for the replacement of chemical additives. CV was adsorbed onto natural zeolite (NZ) via a new vacuum adsorption method. The novel nanohybrid CV@NZ with a high CV content contained 61.7%wt. CV. Pure NZ and the CV@NZ nanohybrid were successfully dispersed in a PLA/triethyl citrate (TEC) matrix via a melt extrusion process to obtain PLA/TEC/xCV@NZ and PLA/TEC/xNZ nanocomposite films with 5, 10, and 15%wt CV@NZ or pure NZ content. The optimum resulting film PLA/TEC/10CV@NZ contained 10%wt. CV@NZ and exhibited self-healable properties, 22% higher tensile strength, 40% higher elongation at break, 45% higher water barrier, and 40% higher oxygen barrier than the pure PLA/TEC matrix. This film also had a high CV release content, high CV control release rate as well as 2.15 mg/L half maximal effective concentration (EC50) and 0.27 mm and 0.16 mm inhibition zones against Staphylococcus aureus and Salmonella enterica ssp. enterica serovar Typhimurium, respectively. This film not only succeeded in extending the shelf life of fresh minced pork, as shown by the total viable count measurements in four days but also prevented the lipid oxidation of fresh minced pork and provided higher nutritional values of the minced meat, as revealed by the heme iron content determination. It also had much better and acceptable sensory characteristics than the commercial packaging paper.

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End groups of poly(Lactide-co-glycolide) (PLGA) play an important role in determining the properties of polymers for use in drug delivery systems. For instance, it has been reported that the encapsulation efficiency in PLGA microspheres varies significantly between ester-terminated and acid-terminated PLGA. More importantly, the in-vivo degradation time of such polymer excipients is influenced by the functional end-group of the copolymer used. The end group distribution in PLGA polymers has been studied using electrospray and matrix-assisted laser-desorption/ionization - high-resolution mass spectrometry. In both cases, the application of these methods is typically limited to PLGA having a molecular weight of up to 4 kDa. 13Carbon-nuclear-magnetic-resonance has also been reported as a method to differentiate and quantify PLGA end groups with a molecular weight up to 136 kDa. However, reported NMR methods take over 12 h per sample, limiting throughput.Cryoprobe NMR can reduce the time required for the process, however such NMR equipment is costly, which makes it unsuitable for the quality control of PLGA. Here, we present a normal-phase liquid chromatography method capable of resolving functionality type distribution (FTD) and, partially, chemical composition distribution (CCD) in commercial PLGA polymers obtained from ring opening polymerization. This method can separate PLGA polymers with a molecular weight of up to 183.0 kDa while also enabling the simultaneous separation of the difference of Lactic acid (LA)/Glycolic acid (GA) ratios. To achieve this, a cross-linked diol column was used with a ternary gradient from HEX to 0.1 % v/v TEA in EA to 0.1 % v/v FA in THF to allow first for the elution of mono-ester terminated PLGA, followed by the di-acid terminated. In addition, a separation of ester-terminated PLGA in the difference of the LA/GA ratio was achieved. This method is expected to aid in understanding the correlation between PLGA's FTD, CCD, and physical properties, facilitating product development and quality control.

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