Antimicrobial Efficacy of Poly (DL‐lactide‐co‐glycolide) (PLGA) Nanoparticles with Entrapped Cinnamon Bark Extract against Listeria monocytogenes and Salmonella typhimurium

Nanoencapsulation of active compounds using poly‐(d,l ‐lactide‐co‐glycolide) (PLGA) is commonly used in the pharmaceutical industry for drug delivery and may have important applications in the food industry. Control of growth of foodborne bacteria with the goals of reducing the number of foodborne illness outbreaks, assuring consumers a safer food supply remains a priority in the food industry. Natural antimicrobials are an excellent way to eliminate pathogens without introducing chemical preservatives that consumers may find undesirable. Cinnamon bark extract (CBE) is an effective pathogen inhibitor isolated from cinnamon spice. PLGA nanoparticles containing CBE were produced using an emulsion‐solvent evaporation method and characterized for size, polydispersity, morphology, entrapment efficiency, in vitro release and pathogen inhibition. PLGA with 2 different ratios of lactide to glycolide (65:35 and 50:50) were used to determine how polymer composition affected nanoparticle characteristics and antimicrobial potency. The size of the nanoparticles ranged from 144.77 to 166.65 nm and the entrapment efficiencies of CBE in 65:35 PLGA and 50:50 PLGA were 38.90% and 47.60%, respectively. The in vitro release profile at 35 °C showed an initial burst effect for both types of PLGA followed by a more gradual release of CBE from the polymer matrix. Both types of PLGA nanoparticles loaded with CBE were effective inhibitors of Salmonella enterica serovar Typhimurium and Listeria monocytogenes after 24 and 72 h at concentrations ranging from 224.42 to 549.23 μg/mL. The PLGA encapsulation improved delivery of hydrophobic antimicrobial to the pathogens in aqueous media.     

Optimised nano-formulation on the bioavailability of hydrophobic polyphenol,curcumin, in freely-moving rats

This study has optimised the poly lactic-co-glycolic acid (PLGA) nano-formulation of curcumin to prolong its retention time in the body and improve bioavailability. High-pressure emulsification–solvent-evaporation was designed to obtain curcumin-loaded PLGA nanoparticles (C-NPs) prepared with 2% of PVA containing 20% sucrose as aqueous phase and dichloromethane as oil phase. The size and entrapment efficiency of C-NPs was 158 ± 10 nm and 46.6 ± 13.5%, respectively. The stable storage time of C-NPs was one month at 4 °C. When curcumin was formulated, a significant increase of curcumin exposure in rat plasma was revealed from the intravenous study (AUC/Dose raised 55%) and the oral study (AUC/Dose increased 21-fold). The oral bioavailability of curcumin at C-NPs was 22-fold higher than conventional curcumin. Excretion results support oral study that absorption of curcumin was significantly increased by nano-formulation. These findings demonstrate that PLGA nano-formulation could potentially be applied to increase bioavailability of hydrophobic polyphenols.     

Active systems based on silver-montmorillonite nanoparticles embedded into bio-based polymer matrices for packaging applications

Silver-montmorillonite (Ag-MMT) antimicrobial nanoparticles were obtained by allowing silver ions from nitrate solutions to replace the Na(+) of natural montmorillonite and to be reduced by thermal treatment. The Ag-MMT nanoparticles were embedded in agar, zein, and poly(ε-caprolactone) polymer matrices. These nanocomposites were tested in vitro with a three-strain cocktail of Pseudomonas spp. to assess antimicrobial effectiveness. The results indicate that Ag-MMT nanoparticles embedded into agar may have antimicrobial activity against selected spoilage microorganisms. No antimicrobial effects were recorded with active zein and poly(ε-caprolactone). The water content of the polymeric matrix was the key parameter associated with antimicrobial effectiveness of this active system intended for food packaging applications.     

Microencapsulated antimicrobial compounds as a means to enhance electron beam irradiation treatment for inactivation of pathogens on fresh spinach leaves

Abstract: Recent outbreaks associated to the consumption of raw or minimally processed vegetable products that have resulted in several illnesses and a few deaths call for urgent actions aimed at improving the safety of those products. Electron beam irradiation can extend shelf‐life and assure safety of fresh produce. However, undesirable effects on the organoleptic quality at doses required to achieve pathogen inactivation limit irradiation. Ways to increase pathogen radiation sensitivity could reduce the dose required for a certain level of microbial kill. The objective of this study was to evaluate the effectiveness of using natural antimicrobials when irradiating fresh produce. The minimum inhibitory concentration of 5 natural compounds and extracts (trans‐cinnamaldehyde, eugenol, garlic extract, propolis extract, and lysozyme with ethylenediaminetetraacetate acid (disodium salt dihydrate) was determined against Salmonella spp. and Listeria spp. In order to mask odor and off‐flavor inherent of several compounds, and to increase their solubility, complexes of these compounds and extracts with β‐cyclodextrin were prepared by the freeze‐drying method. All compounds showed bacteriostatic effect at different levels for both bacteria. The effectiveness of the microencapsulated compounds was tested by spraying them on the surface of baby spinach inoculated with Salmonella spp. The dose (D₁₀ value) required to reduce the bacterial population by 1 log was 0.190 kGy without antimicrobial addition. The increase in radiation sensitivity (up to 40%) varied with the antimicrobial compound. These results confirm that the combination of spraying microencapsulated antimicrobials with electron beam irradiation was effective in increasing the killing effect of irradiation. Practical Application: Foodborne illness outbreaks attributed to fresh produce consumption have increased and present new challenges to food safety. Current technologies (water washing or treating with 200 ppm chlorine) cannot eliminate internalized pathogens. Ionizing radiation is a viable alternative for eliminating pathogens; however, the dose required to inactivate these pathogens is often too high to be tolerated by the fresh produce without undesirable quality changes. This study uses natural antimicrobial ingredients as radiosensitizers. These ingredients were encapsulated and applied to fresh produce that was subsequently irradiated. The process results in high level of microorganism inactivation using lower doses than the conventional irradiation treatments.     

Inhibition and inactivation of Listeria monocytogenes and Escherichia coli O157:H7 colony biofilms by micellar-encapsulated eugenol and carvacrol

The antimicrobial efficacy of carvacrol and eugenol, two essential oil compounds, encapsulated in a micellar nonionic surfactant solution on four strains of Listeria monocytogenes (Scott A, 101, 108, and 310) and four strains of Escherichia coli O157:H7 (H1730, E0019, F4546, and 932) growing as colony biofilms was investigated. Carvacrol and eugenol were encapsulated in Surfynol 485W at concentrations ranging from 0.3 to 0.9% (wt/wt) at a surfactant concentration of 5% (wt/wt). Colony biofilms were grown on polycarbonate membranes resting on agar plates containing antimicrobial formulations. Cells were enumerated after 0, 3, 6, 9, 24, 48, and 72 h of incubation. Colony biofilms of all E. coli O157:H7 strains were more sensitive to both antimicrobial systems than L. monocytogenes strains. Surface-grown E. coli O157:H7 viable cell numbers decreased below detectable levels after exposure to encapsulated essential oil compounds for > 3 h at all tested concentrations, except for E. coli O157:H7 F4546, which grew slowly in the presence of < 0.5% (wt/wt) eugenol. L. monocytogenes Scott A and 101 were more resistant to eugenol than carvacrol at sublethal concentrations (< 0.5% [wt/wt]). Carvacrol was effective at any concentration against L. monocytogenes 108, whereas concentrations of > 0.5% (wt/wt) eugenol were required for inactivation. L. monocytogenes 310 was equally sensitive to both essential oil compounds. Results suggest that surfactant-encapsulated generally recognized as safe essential oil compounds may offer a new means to control the growth of food pathogens such as E. coli O157:H7 and L. monocytogenes on food contact surfaces.     

Isolation and identification of caffeine-degrading bacteria from coffee plantation area

Decaffeination of food and beverage products is in high demand. In this study, a caffeine-degrading bacterium Burkholderia spp. was isolated from coffee plantation area of Chiang Mai province of Thailand. The bacterial isolates were first identified by morphological, physiological, and biochemical tests followed by 16S rDNA analysis. The bacterial isolate of Burkholderia spp. showed 45.5% of caffeine degradation in caffeine containing media (2.5 g/L) after 110 h of incubation period. Burkholderia spp. showed only 2.6% caffeine degradation when exposed to high concentrations of caffeine containing medium (20 g/L). The growth rate of Burkholderia spp. declined with the increase in the caffeine concentration, which indicated the inhibiting effect of caffeine at very high concentrations. The maximum growth rate of 0.053 h^?1 was observed at 2.5 g/L of caffeine. Overall due to high caffeine tolerance and biodegradation of caffeine, Burkholderia spp. can be effectively used to degrade caffeine from agro-industrial wastes targeted for value added food applications and environmental remediation.     

响应面试验优化猴头菌素-PLGA微球制备工艺及其体外释药性能

目的:以聚乳酸-羟基乙酸共聚物(poly(lactic-co-glycolic acid),PLGA)为载体,采用乳化溶剂挥发法制备猴头菌素缓释微球,并对其体外药物释放行为进行考察。方法:通过单因素试验,以包封率为评价指标,考察影响微球质量的因素,采用响应面试验法进行优化,筛选出最佳工艺条件。结果:最佳工艺为芯壁比(猴头菌素与PLGA质量比)1∶1.64、PLGA质量分数15%、搅拌速率1 200 r/min。最佳条件制备的猴头菌素微球表面光滑圆整,包封率为99.66%,微球体外384 h累计释放率达84.30%。结论:以PLGA为载体材料,采用乳化-溶剂挥发法可以制备包封率较高的猴头菌素微球,体外释药实验也表明该微球具有明显的缓释作用。     

Stabilized nanosilver based antimicrobial poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanocomposites of interest in active food packaging

Antimicrobial silver based nanocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) were successfully synthesized and characterized. For the synthesis, a masterbatch of in situ stabilized silver nanoparticles (AgNPs) produced into a mixed microbial cultures based poly(3-hydroxybutyrate-co-18 mol%-3-hydroxyvalerate) (PHBV18) was used, which was diluted by melt compounding with a commercial poly(3-hydroxybutyrate-co-3 mol%-3-hydroxyvalerate) (PHBV3) material. The incorporated AgNPs (0.04 wt.%) led to a surprising oxygen permeability drop of ca. 56% compared to the neat polymer. The thermal stability and optical properties of the nanocomposites were not significantly modified as compared to the neat PHBV3. Moreover, the antimicrobial performance of the PHBVs-AgNPs films against two of the most common food borne pathogens, Salmonella enterica and Listeria monocytogenes, showed a strong and sustained (even after seven-months) antibacterial activity. This study provides an innovative route to generate fully renewable and biodegradable antimicrobial nanocomposites that could potentially be of interest in film and coating applications such as active food packaging.Industrial relevanceAs a response to the consumers for more safety foodstuffs and ecofriendly packaging materials, this work presents a novel methodology to develop antimicrobial packaging by using biodegradable materials obtained from industrial food by-products in combination of an industrially meaningful melt blending process. The methodology here applied allows the use of low doses of stabilized silver nanoparticles in the polymer matrix, without additives, which exhibits prolonged antimicrobial activity against food borne pathogens and enhanced oxygen barrier properties. These materials are of great interest in the development and design of biodegradable active food packaging materials and antibacterial food contact surfaces with the additional advantage that they can be easily scale-up.     

Inhibition of Alicyclobacillus acidoterrestris spores by natural compounds

The aim of this study was to evaluate the antimicrobial effectiveness of some natural compounds (cinnamaldehyde, eugenol, limonene) and sodium benzoate against two strains of Alicyclobacillus acidoterrestris (c8 and γ4). The antimicrobial compounds (10–500 ppm) were solved in malt extract broth, inoculated separately with 10³ spores mL⁻¹ of each strain; the samples were incubated at 44 °C and the outgrowth of spores was evaluated every day by measuring the absorbance of the medium at 420 nm; inoculated samples without active compounds were used as controls. The results pointed out that limonene was not effective in inhibiting the outgrowth of A. acidoterrestris spores; 100 ppm of cinnamaldehyde or sodium benzoate slowed the spore germination, whereas 500 ppm of eugenol inhibited the growth of microbial targets for 13 days. Strain c8 was more resistant than isolate γ4 and cinnamaldehyde was the most effective compound in inhibiting the germination of A. acidoterrestris spores.     

Natural Antimicrobial Edible Coatings for Microbial Safety and Food Quality Enhancement

Natural antimicrobial agents have been investigated as alternatives to synthetic ones for ensuring food safety and quality. However, the practical use of these preservatives in the food industry is limited due to their negative impact on the odor and taste of food products, as well as the early loss of functionality due to their rapid diffusion and interaction with food components. The incorporation of natural antimicrobial agents into edible coatings has been investigated to control diffusion of active compounds and maintain their concentrations at a critical level on a food surface. Recently, nanoencapsulating and multilayered/nanolaminate delivery systems have emerged as promising tools to enhance the functionality of edible coatings. This review highlights the potential use of polymeric edible coatings for the incorporation of natural antimicrobial agents and the improvement of their controlled release in food systems. The methods used to assess the antimicrobial activity of encapsulated natural antimicrobial agents and the most recent findings regarding the application of nanoencapsulating and multilayered/nanolaminate delivery systems in food products are also discussed.     

Controlled release of antimicrobial compounds from highly swellable polymers

The suitability of antimicrobial release films made from highly swellable polymers for use in food packaging was evaluated. The possibility of modulating the release kinetics of active compounds either by regulating the degree of cross-link of the polymer matrix or by using multilayer structures was addressed. The release kinetics of lysozyme, nisin, and sodium benzoate (active compounds with different molecular weights) were determined at ambient temperature (25 degrees C). The effectiveness of the proposed active films in inhibiting microbial growth was addressed by determining the antimicrobial efficiency of the released active compounds. Micrococcus lysodeikticus, Alicyclobacillus acidoterrestris, and Saccharomyces cerevisiae were used to test the antimicrobial efficiency of released lysozyme, nisin, and sodium benzoate, respectively. Results indicate that the release kinetics of both lysozyme and nisin can be modulated through the degree of cross-link of the polymer matrix, whereas multilayer structures need to be used to control the release kinetics of sodium benzoate. All the active compounds released from the investigated active films were effective in inhibiting microbial growth.     

Immobilization of naringinase from Aspergillus niger CECT 2088 in poly(vinyl alcohol) cryogels for the debittering of juices

Naringinase, induced from Aspergillus niger CECT 2088 cultures, was immobilized into a polymeric matrix consisting of poly(vinyl alcohol) (PVA) hydrogel, cryostructured in liquid nitrogen, to obtain biocatalytically active beads. The effects of matrix concentration, enzyme load and pH on immobilization efficiency were studied. Between 95% and 108% of the added naringinase was actively entrapped in PVA cryogel, depending on the conditions of immobilization used. The optimal conditions were: 8% (w/v) PVA at pH 7 and 1.6–3.7 U ml⁻¹ of enzyme load. The pH/activity profiles revealed no change in terms of shape or optimum pH (4.5) upon immobilization of naringinase. However, the optimum temperature was shifted from 60 °C to 70 °C and the activation energy of reaction, E_a, was decreased from 8.09 kJ mol⁻¹ to 6.36 kJ mol⁻¹ by immobilization. The entrapped naringinase could be reused through six cycles (runs of 24 h at 20 °C), retaining 36% efficacy for the hydrolysis of naringin in simulated juice.     

Functional Properties of Plasticized Bio-Based Poly(Lactic Acid)_Poly(Hydroxybutyrate) (PLA_PHB) Films for Active Food Packaging

Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly(3-hydroxybutyrate) (PHB) and incorporating lactic acid oligomers (OLA) as plasticizers and carvacrol as active agent were extruded and fully characterized in their functional properties for antimicrobial active packaging. PLA_PHB films showed good barrier to water vapor, while the resistance to oxygen diffusion decreased with the addition of OLA and carvacrol. Their overall migration in aqueous food simulant was determined and no significant changes were observed by the addition of carvacrol and OLA to the PLA_PHB formulations. However, the effect of both additives in fatty food simulant can be considered a positive feature for the potential protection of foodstuff with high fat content. Moreover, the antioxidant and antimicrobial activities of the proposed formulations increased by the presence of carvacrol, with enhanced activity against Staphylococcus aureus if compared to Escherichia coli at short and long incubation times. These results underlined the specific antimicrobial properties of these bio-films suggesting their applicability in active food packaging.     

Development of moisture‐absorbing and antioxidant active packaging film based on poly(vinyl alcohol) incorporated with green tea extract and its effect on the quality of dried eel

Active packaging film with functions of moisture‐absorbing and antioxidant activity was developed based on poly(vinyl alcohol) (PVA) incorporated with green tea extract (GTE). The effects of GTE concentrations of 0, 0.5, 1, 1.5, and 2% on the physical, structural, and antioxidant properties of PVA films were investigated. The PVA film containing 2% GTE had lower moisture absorbing efficiency relatively and better antioxidant activity through DPPH radical‐scavenging ability experiment. A packaging system of GTE‐incorporated PVA films was applied to package dried eel and quality of dried eel was evaluated during storage. The result showed that dried eel packed with GTE‐incorporated PVA films showed lower weight change, peroxide value and TBARS value during storage than that packed without PVA films or with PVA films but no GTE. The PVA film containing 2% GTE showed the best quality protective effectiveness to prevent the dried eel from absorbing moisture and oxidizing of lipid.

Practical applications

Poly(vinyl alcohol) (PVA) is a synthetic polymer that is widely used in packaging applications because of its excellent film forming, biodegradability, good mechanical, and gas barrier properties. The present study evidenced that the PVA films incorporated with GTE showed good quality protective effectiveness to prevent the dried eel packed with these films from absorbing moisture and oxidizing of lipid. This active packaging film could be used as inner layer or intermediate layer in the composite packaging film system to improve the storage quality of moisture‐sensitive and high‐fat food. Based on this concept, the moisture‐absorbing agents and antioxidant can be incorporated into the packaging structures to develop an active multifunctional food packaging material potentially to remove or reduce moisture inside the food packaging system instead of desiccants and preservative added in the food.     

Inhibition of Bacillus subtilis and Listeria innocua by nisin in combination with some naturally occurring organic compounds

The application of combined preservative factors (hurdle technology) is very effective in controlling the growth of food spoilage and foodborne pathogenic bacteria. Antimicrobial activity of nisin alone and in combination with some natural organic compounds (carvacrol, cinnamic acid, eugenol, diacetyl, and thymol) on the growth of gram-positive bacteria Bacillus subtilis and Listeria innocua was-investigated. All the organic compounds tested exhibited antimicrobial activity against the microorganisms used; however, the MICs varied between 0.8 and 15.0 mM depending on the potency of the compound or the sensitivity of the target strain. Investigation of the interaction between the organic compounds and nisin against the test organisms revealed different patterns, varying from synergistic to antagonistic. Combinations of nisin with carvacrol, eugenol, or thymol resulted in synergistic action against both test organisms. Activity of nisin and cinnamic acid together was synergistic against L. innocua, but only additive against B. subtilis. In contrast, the combination of diacetyl and nisin resulted in an antagonistic effect against both test organisms. This study highlights the potential of the combination of these compounds with nisin to inhibit pathogen growth in food.     

Influence of droplet size on the efficacy of oil-in-water emulsions loaded with phenolic antimicrobials

In this study we investigated the effect of droplet size on the antimicrobial activity of emulsions containing two essential oil compounds that are known for their antimicrobial effectiveness: carvacrol and eugenol. Coarse emulsions were prepared by blending a triacylglyceride (Miglyol 812N) containing various concentrations of carvacrol or eugenol (5, 15, 30, 50 wt%) at an oil droplet mass fraction of 10 wt% with an aqueous phase containing 2 wt% Tween 80(?). Premixes were then further dispersed using a high shear blender, a high pressure homogenizer at different pressures or an ultrasonicator to produce droplets with a variety of mean diameters. Microscopy and light scattering storage stability studies over 10 days indicated that manufactured emulsions were stable, i.e. that no aggregation, creaming or other destabilization mechanisms occurred and droplet size distributions remained unchanged. The antimicrobial activity of emulsions was assessed against two model microorganisms, the Gram negative Escherichia coli C 600 and the Gram positive Listeria innocua, by determining growth over time behavior. The analysis yielded the unexpected result that emulsions with larger droplet sizes were more effective at inhibiting growth and inactivating cells than smaller ones. For example, emulsions with a mean oil droplet size of 3000 nm at a concentration of 800 ppm carvacrol completely inhibited L. innocua, while for 80 nm emulsions, only a delay of growth could be observed. Measurements of the concentration of the antimicrobial compounds in the aqueous phase indicated that concentrations of eugenol and carvacrol decreased with decreasing oil droplet sizes. Determination of interfacial tension further showed that eugenol and carvacrol are preferentially located in the oil-water interfaces. Theoretical calculations of Tween 80(?) concentrations needed to saturate interfaces suggested that in small emulsions for the given formulation less Tween 80(?) micelles are present in the aqueous phase. We therefore attribute the fact that antimicrobial nanoemulsions are less active than macroemulsions due to an increased sequestering of antimicrobials in emulsion interfaces and a decreased solubilization in excess Tween 80(?) micelles.     

Influence of antimicrobial compounds and modified atmosphere packaging on radiation sensitivity of Listeria monocytogenes present in ready-to-use carrots (Daucus carota)

Radiosensitization of Listeria monocytogenes was determined in the presence of trans-cinnamaldehyde, Spanish oregano, winter savory, and Chinese cinnamon on peeled minicarrots packed under air or under a modified atmosphere (60% O2, 30% CO2, and 10% N2). Samples were inoculated with L. monocytogenes HPB 2812 serovar 1/2a (106 CFU/g) and were coated separately with each active compound (0.5%, wt/wt) before being packaged under air or the modified atmosphere and irradiated at doses from 0.07 to 2.4 kGy. Results indicated that the bacterium was more resistant to irradiation under air in the absence of active compound. The dose required to reduce L. monocytogenes population by 1 log CFU (D10) was 0.36 kGy for samples packed under air and 0.17 kGy for those packed under the modified atmosphere. The active compounds evaluated in this study had an effect on the radiation sensitivity of L. monocytogenes on carrots. The most efficient compound was trans-cinnamaldehyde, where a mean 3.8-fold increase in relative radiation sensitivity was observed for both atmospheres compared with the control. The addition of winter savory and Chinese cinnamon produced a similar increase in relative radiation sensitivity but only when samples where packed under modified atmosphere conditions.     

Effects of cyclodextrins on the antimicrobial activity of plant-derived essential oil compounds

Essential oils (EOs) from plants are considered to be a safer alternative when compared to synthetic antimicrobial food additives. However, a major drawback of many EOs is their hydrophobic nature, which makes them insoluble in water based media and matrices. Although cyclodextrins (CDs) can increase the solubility of EO compounds, the effects of CDs on the antimicrobial activity of EOs have not been reported. In this paper, four different EO compounds (carvacrol, eugenol, linalool and 2-pentanoylfuran) were chosen to study the influence of CDs on the solubility and antimicrobial activity on bacteria and yeast. The greatest enhancement with regards to solubility of the four test compounds was achieved by hydroxypropyl-β-CD. In most instances, not only were the minimal antimicrobial concentrations of EO compounds decreased, but the interactivity of two combined EO compounds could be strengthened by the co-addition of CDs. Furthermore, the combination of carvacrol with hydroxypropyl-β-CD caused a marked change in the major membrane lipid composition of all microorganisms investigated; while scanning electron microscopy revealed that cellular integrity was significantly affected by 2× MIC, ultimately resulting in cell lysis.     

Enhanced antimicrobial activity of nisin-loaded liposomal nanoparticles against foodborne pathogens

This study was designed to evaluate the prolonged antimicrobial stability of nisin-loaded liposome (LipoN) nanoparticles against Listeria monocytogenes and Staphylococcus aureus. The sizes of bare liposomes and LipoN were uniformly distributed between 114 and 125 nm. The nanoparticles were homogeneously dispersed in water with less than 0.2 of polydispersity index. The zeta potential value of LipoN was +17.1 mV due to the positive charged nisin, attaining 70% of loading efficiency. The minimum inhibitory concentration of LipoN against L. monocytogenes and S. aureus was 320 international unit/mL. The LipoN significantly enhanced the antimicrobial stability in brain heart infusion agar compared to free nisin. The numbers of L. monocytogenes and S. aureus exposed to LipoN were effectively reduced by more than 6 log colony-forming unit/mL after 48 and 72 h of incubation, respectively. These results provide useful information for the development of antimicrobial delivery system to improve food safety.     

胶原蛋白改性聚乳酸-羟基乙酸载药纳米纤维膜的制备及其性能

为改善聚乳酸-羟基乙酸共聚物(PLGA)基药物载体的降解性能和释药性能,以PLGA为基材,以胶原蛋白(Col)为改性材料,以阿霉素(DOX)为药物模型,利用静电纺丝技术制备得到PLGA/Col/DOX纳米纤维膜,探究了胶原蛋白对其亲疏水性、体外降解性、释药性能及细胞相容性的影响。结果表明:PLGA与Col以3:1的质量比复合制得的纳米纤维膜性能最佳;经胶原蛋白复合改性后,纳米纤维膜的接触角由未改性的93.5°降至51.5°,亲水性显著提高;胶原蛋白改性可大幅提高PLGA的降解性,改性后纳米纤维膜30 d的质量损失速率由未改性的3.5%增加至19%,且改性后纳米载药纤维膜的药物释放速率和细胞相容性明显提高,有利于细胞黏附增殖。