In vitro degradation and drug‐release behavior of electrospun,fibrous webs of poly(lactic‐co‐glycolic acid)

Ultrafine fibrous webs of poly(lactide‐co‐glycolic acid) (PLGA) containing the bactericidal antibiotic drug rifampin were prepared by electrospinning, and their properties were investigated for wound‐dressing applications. Because PLGA is a biodegradable and biocompatible polymer, it is one of the best materials for the preparation of wound‐dressing substrates. Through this investigation of PLGA/rifampin electrospun webs, we found that the in vitro degradation reached approximately 60% in 10 days, and the drug release from the webs showed a fast and constant profile suitable for wound‐dressing applications. Also, we observed that both the web‐degradation rate and the drug‐release rate increased as the drug concentration in the PLGA/rifampin electrospun webs and the content level of glycolide units in the PLGA polymer matrix increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Zein nanoparticle‐embedded electrospun PVA nanofibers as wound dressing for topical delivery of anti‐inflammatory diclofenac

Bioactive wound dressings from poly(vinyl alcohol) (PVA) and zein nanoparticles (NPs) loaded with diclofenac (DLF) were prepared successfully by the single jet electrospinning method. DLF‐loaded zein NPs with an average diameter of ～228 nm were prepared using anti‐solvent precipitation method. The formulation of zein:DLF 1:1 exhibited optimum encapsulation efficiency of 47.80%. The NPs were characterized by dynamic light scattering, zeta‐potential measurement, and differential scanning calorimetry. In vitro, drug release profiles of the DLF‐loaded zein NPs, and PVA–zein NPs were also studied within 120 h and showed the release efficiency of nearly 80% from zein NPs. A more controlled release of DLF was achieved by embedding the zein NPs in the PVA nanofibers. Fourier transform infrared spectroscopy was used to analyze possible interactions between different components of the fabricated dressings. The mechanical properties of the developed dressings were also evaluated using uniaxial tensile testing. Young's modulus (E) of the dressings decreased after inclusion of zein NPs within the PVA nanofibers. Moreover, fibroblast culturing experiments proved that the composite dressings supported better cell attachment and proliferation compared to PVA nanofibers, by exhibiting moderate hydrophilicity. The results suggested that the electrospun composite dressing of PVA nanofibers and zein NPs is a promising topical drug‐delivery system and have a great potential for wound healing application. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46643.     

Fabrication of althea officinalis loaded electrospun nanofibrous scaffold for potential application of skin tissue engineering

The Althea Officinalis (AO) extract is well known as a traditional herbal drug for its wound healing ability owing to the anti-inflammatory and antimicrobial properties. Furthermore, its mucilaginous properties provide moisturizing and nutritional effects on skin cell proliferation. Therefore, AO extract can be applied in the temporary skin substitute for the ability to expedite the therapy duration. In this study, different concentrations of AO extract (0, 5, 10, 15, and 20 wt %) were incorporated into the nanofibrous scaffolds to study their potential for the skin tissue repairing. The desired scaffolds were prepared by electrospinning the blend of poly(ε -caprolactone) and gelatin as a synthesized and natural polymer. The electrospun nanofibers were characterized by SEM, FTIR, DSC, TGA, tensile, AO extract release, and cellular culture tests. This study proposed incorporating the AO extract into the nanofibrous scaffolds for accelerating the skin tissue repairing and the optimized amount of AO extract as about 15% was introduced for offering the most desirable electrospun scaffolds for this application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48587.     

Herbal drug incorporated antibacterial nanofibrous mat fabricated by electrospinning: An excellent matrix for wound dressings

Nano‐components and nano‐systems for health care and medical applications are the focus of many research projects worldwide. Nanofibrous membranes are highly soft materials with high surface‐to‐volume ratios, and therefore can serve as excellent carriers for therapeutic agents that are antibacterial or accelerate wound healing. PCL/PVP Nanofiber mat containing chloroform: methanol (4:1) crude bark extract of Tecomella undulata, a medicinal plant widely known for its traditional medical applications including its wound healing ability, were prepared and evaluated for their antibacterial properties. With good drug stability and high drug‐loading efficacy, the incorporation of herbal extract in the polymer media did not appear to influence the morphology of the resulting fibers, as both the drug‐free and the drug‐loaded nanofibers remained unaltered, microscopically. Activity was tested against standard strains of Pseudomonas aeruginosa MTCC 2297, Staphylococcus aureus ATCC 933, Escherichia coli (IP‐406006). Extract loaded PCL/PVP nanofiber mat were able to inhibit the growth of the bacterial strains which indicate that it could act not only as a drug delivery system but also in the treatment of wound healing or dermal bacterial infections thereby proving a potential application for use as a wound dressing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fibro‐porous polycaprolactone membrane containing extracts of Biophytum sensitivum: A prospective antibacterial wound dressing

A fibro‐porous wound dressing with antibacterial activity was fabricated from polycaprolactone (PCL) solution containing crude extract of biophytum sensitivum (BS) a potential antibacterial herbal drug. Scanning electron microscopy revealed the smooth fibrous morphology of the PCL membrane, whereas the drug‐loaded PCL formed fibers with more interconnective junctions with an average fiber diameter between 1 and 3 μm. Physical characterization of the membrane revealed that it has excellent mechanical stability, water vapor transmission rate and that it promotes water uptake. The release characteristics by total immersion method in phosphate buffer and acetate buffer displayed an increase in drug release with time. Finally, the antibacterial activity of the membrane was tested against standard strains of Staphylococcus aureus and Escherichia coli. PCL membranes loaded with the drug extracts were able to inhibit the growth of bacterial strains which indicated that this fibro‐porous membrane could act as a potential wound‐dressing material to treat various wounds. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation and drug‐release behavior of minocycline‐loaded poly[hydroxyethyl methacrylate‐co‐poly(ethylene glycol)–methacrylate] films

In this work, biocompatible hydrogel matrices for wound‐dressing materials and controlled drug‐release systems were prepared from poly[hydroxyethyl methacrylate‐co‐poly(ethylene glycol)–methacrylate] [p(HEMA‐co‐PEG–MA] films via UV‐initiated photopolymerization. The characterization of the hydrogels was conducted with swelling experiments, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis (differential scanning calorimetry), and contact‐angle studies. The water absorbency of the hydrogel films significantly changed with the change of the medium pH from 4.0 to 7.4. The thermal stability of the copolymer was lowered by an increase in the ratio of poly(ethylene glycol) (PEG) to methacrylate (MA) in the film structure. Contact‐angle measurements on the surface of the p(HEMA‐co‐PEG–MA) films demonstrated that the copolymer gave rise to a significant hydrophilic surface in comparison with the homopolymer of 2‐hydroxyethyl methacrylate (HEMA). The blood protein adsorption was significantly reduced on the surface of the copolymer hydrogels in comparison with the control homopolymer of HEMA. Model antibiotic (i.e., minocycline) release experiments were performed in physiological buffer saline solutions with a continuous flow release system. The amount of minocycline release was shown to be dependent on the HEMA/PEG–MA ratio. The hydrogels have good antifouling properties and therefore are suitable candidates for wound dressing and other tissue engineering applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Poly(vinyl alcohol)/chitosan/honey/clay responsive nanocomposite hydrogel wound dressing

Many efforts have been made to develop modern wound dressings to overcome limitations of traditional ones. Smart nanocomposite hydrogels are appropriate candidates. In this work, a novel responsive nanocomposite hydrogel based on poly(vinyl alcohol)/chitosan/honey/clay was developed and evaluated as a novel wound dressing. The morphology and properties of synthesized nanocomposite hydrogels loaded with honey as a drug model were investigated. The exfoliated morphology of nanocomposite was confirmed by X‐ray diffractometry. Swelling studies were performed at 20 and 37 °C at various pH. The results showed that swelling increased as a result of temperature rise and maximum swelling occurred at a pH of 2. In vitro release of honey was also studied at the same conditions. Corresponding results indicated faster honey release rate at higher pH values. MTT results exhibited no cytotoxicity in nanocomposite hydrogel system. Investigation of antibacterial activity revealed more than 99% antibacterial activity for proposed system. In vivo results confirmed the wound healing ability of developed system. Generally, appropriate properties of proposed system made it ideal in wound dressing applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46311.     

Electrospun core–shell nanofibers for drug encapsulation and sustained release

Fabrication of core–shell nanofibers by coaxial electrospinning system suited for drug delivery applications was investigated based on tetracycline hydrochloride (TCH) as the core and poly(lactide‐co‐glycolide) as the shell materials. Comparison of drug release from monolithic fibers (blend electrospinning) and core–shell structures was performed to evaluate the efficacy of the core–shell morphology. The nanofibrous webs are potentially interesting for wound healing purposes since they can be maintained for an adequate length of time to gradually disinfect a local area without the need of bandage renewal. Further, our studies showed the potential of core–shell nanostructures for sustained drug release, which also suppressed the burst release effect from 62 to 44% in the first 3 hours by adding only 1 wt% TCH to the polymeric shell. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

Magnetic nanoparticles embedded in pectin‐based hydrogel for the sustained release of diclofenac sodium

A supermagnetic polysaccharide‐based nanocomposite gel has been developed as a potential drug delivery system. The gel was made via graft copolymerization of 2‐acrylamido‐2‐methylpropanesulfonic acid on pectin using ammonium peroxodisulfate as an initiator and N,N‐methylenebisacrylamide as a crosslinker under microwave irradiation. The magnetic nanoparticles (MNPs) were incorporated within the gel network via an in situ method of diffusion of Fe²⁺/Fe³⁺ followed by reduction with ammonia solution. The graft copolymer gel and its nanocomposite were characterized using attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and transmission electron microscopy. The magnetic properties of the nanocomposite were measured using a vibrating sample magnetometer and mechanical properties using a tensile compressive tester. The gel was evaluated for adsorption and release of the drug diclofenac sodium. The presence of MNPs is observed to enhance significantly the mechanical properties, swelling capacity, drug loading and release ability of the graft polymer gel. The increased porosity of the gel network and higher surface area of MNPs allowed for 20% higher adsorption of diclofenac sodium molecules compared to the parent nonmagnetic gel. About 95% of the loaded drug was released from the MNP‐containing gel. The drug release pattern followed first‐order kinetic model and the Higuchi square root model, indicating swelling‐controlled diffusion to be the mode of drug release. © 2018 Society of Chemical Industry     

Preparation,characterization, antibacterial properties,and hemostatic evaluation of ibuprofen‐loaded chitosan/gelatin composite films

Ibuprofen‐loaded chitosan/gelatin (CS/GE) composite films were fabricated in this work. The morphology of the composite film was investigated using scanning electron microscopy. The functional groups of the composite film before and after crosslinking were characterized using Fourier transform infrared spectroscopy. Meanwhile, the mechanical properties, antibacterial performance, cytocompatibility, and hemostatic activity of the composite films were investigated. The results show that the amount of CS affected the mechanical properties and liquid uptake capacities of the composite films. The composite film showed better bactericidal activity against Staphylococcus aureus than Escherichia coli. In vitro drug‐release evaluations showed that crosslinking could control the drug‐release rate and period in wound healing. Both types of CS/GE and drug‐loaded CS/GE composite films also showed excellent cytocompatibility in cytotoxicity assays. The hemostatic evaluation indicated that the composite film crosslinked by glutaraldehyde in rabbit livers had a dramatic hemostatic efficacy. Therefore, ibuprofen‐loaded CS/GE composite films are potentially applicable as a wound dressing material. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45441.     

β‐cyclodextrin‐conjugated hyaluronan hydrogel as a potential drug sustained delivery carrier for wound healing

In order to develop a potential drug sustained delivery carrier suitable for wound healing, a series of β‐cyclodextrin conjugated hyaluronan hydrogels (β‐CD‐HA) with adjustable crosslink densities were synthesized and characterized, meanwhile the delivery kinetics and mechanism of diclofenac as a model anti‐inflammatory drug from these hydrogels were investigated. By controlling the feeding molar ratio of β‐CD/HA, a β‐CD substitution degree of 4.65% was obtained by ¹H‐NMR analysis. The incorporation of β‐CD modification had little effect on the internal porous structure, water swelling ratio, and rheological property of HA hydrogel, which however were influenced by the crosslink density. Although the crosslink density had an influence on the drug loading and release profile by altering the water swelling property, the interaction between β‐CD and drug was the primary factor for the high loading capacity and long‐term sustained delivery of diclofenac. The semiempirical equation fit showed that the release of diclofenac from HA‐based hydrogels followed a pseudo‐Fickian diffusion mechanism. By the aid of β‐CD and controlled crosslink density, a β‐CD‐HA hydrogel with a diclofenac sustained delivery period of over 28 days and desirable physicochemical properties was achieved, which will be a promising drug sustained delivery carrier for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43072.     

Temperature/pH/magnetic triple‐sensitive nanogel–hydrogel nanocomposite for release of anticancer drug

Hydrogels, nanogels and nanocomposites show increasing potential for application in drug delivery systems due to their good chemical and physical properties. Therefore, we were encouraged to combine them to produce a new compound with unique properties for a long‐term drug release system. In this regard, the design and application of a nanocomposite hydrogel containing entrapped nanogel for drug delivery are demonstrated. To this aim, we first prepared an iron oxide nanocomposite nanogel based on poly(N‐isopropylacrylamide)‐co‐((2‐dimethylaminoethyl) methacrylate) (PNIPAM‐co‐PDMA) grafted onto sodium alginate (NaAlg) as a biocompatible polymer and iron oxide nanoparticles (ION) as nanometric base (PND/ION‐NG). This was then added into a solution of PDMA grafted onto NaAlg. Through dropwise addition of mixed aqueous solution of iron salts into the prepared polymeric solution, a novel hydrogel nanocomposite with excellent pH, thermal and magnetic responsivity was fabricated. The synthesized samples were fully characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy with energy‐dispersive X‐ray analysis, vibrating sample magnetometry and atomic force microscopy. A mechanism for the formation of PNIPAM‐co‐PDMA/NaAlg‐ION nanogel–PDMA/NaAlg‐ION hydrogel and PND/ION nanogel is suggested. Swelling capacity was measured at various temperatures (25 to 45 °C), pH values (from 2 to 11) and magnetic field and under load (0.3 psi) and the dependence of swelling properties of the nanogel–hydrogel nanocomposite on these factors was well demonstrated. The release rate of doxorubicin hydrochloride (DOX) as an anticancer drug was studied at different pH values and temperatures in the presence and absence of a magnetic field. The results showed that these factors have a high impact on drug release from this nanocomposite. The result showed that DOX release could be sustained for up to 12.5 days from these nanocomposite hydrogels, significantly longer than that achievable using the constituent hydrogel or nanogel alone (<1 day). The results indicated that the nanogel–hydrogel nanocomposite can serve as a novel nanocarrier for anticancer drug delivery. © 2019 Society of Chemical Industry     

Chitosan–poly(aminopropyl/phenylsilsesquioxane) hybrid nanocomposite membranes for antibacterial and drug delivery applications

We fabricated hybrid (CSSQ) membranes from chitosan and poly(aminopropyl/phenylsilsesquioxane) (PAPSQ) blends via a sol–gel reaction and solution casting followed by crosslinking with glutaraldehyde. The CSSQ membranes were then used for loading of 5‐fluorouracil (5‐FU) as an anticancer drug as well as templates for the production of silver nanoparticles (AgNPs). The physicochemical properties of the CSSQ membranes were examined using UV‐visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis and scanning electron microscopy (SEM). SEM results showed the controllable formation of AgNPs around PAPSQ. CSSQ–Ag nanocomposite membranes exhibited good antibacterial activity towards both Escherichia coli and Bacillus subtilis, while the CSSQ membranes worked as good carriers for controlled release of 5‐FU as model drug. The results suggest that both CSSQ and CSSQ–Ag nanocomposite membranes can be potentially applied for biomedical applications such as controlled release carriers as well as antibacterial wound dressing materials. © 2014 Society of Chemical Industry     

Covalent attachment of quaternary ammonium compounds to a polyethylene surface via a hydrolyzable ester linkage: Basis for a controlled‐release system of antiseptics from an inert surface

The colonization of medical devices such as catheters, topical wound dressings, and surgical implants by micro‐organisms is an ongoing problem, particularly as many strains of bacteria are becoming resistant to antibiotics. Such a problem may be addressed by a material surface that is able to provide a slow release of a disinfectant during its period of usage. To achieve this objective, a novel material was prepared in which a quaternary ammonium salt was covalently bound onto a polyethylene backbone via a hydrolyzable ester linkage, which provided a slow release of the disinfecting agent. A low‐density polyethylene film was treated with glow discharge followed by the graft polymerization of acrylic acid. A tertiary amine function was introduced onto the film by the esterification of the carboxylic acid groups, via an acid chloride intermediate, with 4‐hydroxy‐N‐methyl piperidine. The tertiary amine on the piperidine was then quaternized with a series of alkyl bromides of various chain lengths. The quaternary ammonium salt was released slowly by the hydrolysis of the ester bond over a 4‐h period. To test the efficacy of the quaternary ammonium function itself, soluble compounds were prepared as follows. 4‐Hydroxy‐N‐methyl piperidine was esterified with acetic anhydride and a corresponding series of quaternary ammonium salts prepared again by a reaction with alkyl bromides of various chain lengths. A preliminary microbiological survey of the materials included an investigation of the effect of the chain length as well as the efficacy of the soluble quaternary salts themselves. As expected, only the longer alkyl chains provided quaternary ammonium salts with bactericidal properties, chain lengths of less than 10 carbon atoms proving ineffective. Both the polymer‐bound and soluble long‐chain quaternary ammonium salts were effective against suspensions of Staphylococcus aureus and Escherichia coli. The results therefore indicate that such a system may well be useful in the development of biomedical materials such as surgical implants or dressings in which a slow release of a disinfectant or other physiologically active agent such as an anti‐inflammatory drug may be required. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 538–545, 2006     

Shape‐memory bioresorbable terpolymer composite with antirestenotic drug

Shape‐memory polymers (SMPs) that combine shape‐memory, biodegradability, and controlled drug release properties are very promising for medical and pharmaceutical application. Moreover, incorporation of antirestenotic drug into SMP biodegradable stent seems to be an interesting solution because of possibility to combine the mechanical support that provides stent and also drug elution. The aim of our study was to analyze the effect of incorporation of sirolimus into poly(l ‐lactide‐co‐glycolide‐co‐trimethylene carbonate) on physicochemical and mechanical properties, degradation, and shape‐memory effect of the terpolymer. For this purpose, sirolimus was incorporated into the terpolymer by injection molding method. It has been demonstrated that drug‐free terpolymer after injection molding characterized insignificant changes in terpolymer composition. Degradation of materials during processing was not observed. Incorporation of drug molecules did not change shape‐memory properties of terpolymer. ¹H‐ and ¹³C‐NMR spectra of poly(lactide‐co‐glycolide‐co‐trimethylene carbonate) confirmed that changes during degradation were similar for terpolymer and terpolymer with sirolimus. Sustained and regular release of sirolimus was observed. The developed material presents potential for biomedical and pharmaceutical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41902.     

Low-methoxyl pectin–zeolite hydrogels controlling drug release promote in vitro wound healing

This study presents the design of novel hydrogel films, based on low-methoxyl (LM) pectin and NaA- or ZnA-zeolite particles, to serve as wound dressing materials with controlled drug delivery properties. We studied the effects of the preparation method of hydrogels, the amounts of crosslinker, drug and zeolite, and the type of cation in zeolites on the drug release mechanisms from the hydrogels. Ionic strengths of both film and external medium dictated the drug release behavior of the films, while the other parameters also played essential roles. NaA-zeolite hydrogels prepared using membrane diffusion controlled system, could reach a drug release ratio of 86% within 5 h. The drug-free hydrogels displayed no cytotoxicity while supporting cell proliferation and migration. Our cost-effective LM pectin–zeolite hydrogels promise to be effective wound dressing materials with controlled drug delivery ability, transparency, good swelling properties, ability to hold fluids, good oxygen transmission rate, and biocompatibility. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47640.     

Composite chitosan/poly(ethylene oxide) electrospun nanofibrous mats as novel wound dressing matrixes for the controlled release of drugs

The aim of this study was to develop novel biomedical electrospun nanofiber mats for controlled drug release, in particular to release a drug directly to an injury site to accelerate wound healing. Here, nanofibers of chitosan (CS), poly(ethylene oxide) (PEO), and a 90 : 10 composite blend, loaded with a fluoroquinolone antibiotic, such as ciprofloxacin hydrochloride (CipHCl) or moxifloxacin hydrochloride (Moxi), were successfully prepared by an electrospinning technique. The morphology of the electrospun nanofibers was investigated by scanning electron microscopy. The functional groups of the electrospun nanofibers before and after crosslinking were characterized by Fourier transform infrared spectroscopy. X‐ray diffraction results indicated an amorphous distribution of the drug inside the nanofiber blend. In vitro drug‐release evaluations showed that the crosslinking could control the rate and period of drug release in wound‐healing applications. The inhibition of bacterial growth for both Escherichia coli and Staphylococcus aureus were achieved on the CipHCl‐ and Moxi‐loaded nanofibers. In addition, both types of CS/PEO and drug‐containing CS/PEO nanofibers showed excellent cytocompatibility in the cytotoxicity assays. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42060.     

Research on the preparation and antibacterial properties of 2‐N‐thiosemicarbazide‐6‐O‐hydroxypropyl chitosan membranes with iodine

The 2‐N‐thiosemicarbazide‐6‐O‐hydroxypropyl chitosan (ATU‐HPCS) was prepared by chitosan grafted hydroxypropyl and thiosemicarbazide through the method of “amino protection‐graft‐deprotection,” while the ATU‐HPCS gel membranes were obtained from gelatin and polyvinyl pyrrolidone as additives, and the ATU‐HPCS membranes with iodine (ATU‐HPCS‐I₂‐M) were prepared by adding the ethanol solution of iodine in the ATU‐HPCS gel membranes. The ATU‐HPCS‐I₂‐M were characterized to evaluate their potential applications as antibacterial materials. The iodine releasing rule of ATU‐HPCS‐I₂‐M showed a sustained‐release effect of iodine, the maximum emission was approximately 0.80%. The inhibition zone diameters of ATU‐HPCS‐I₂‐M against Staphylococcus aureus (as Gram‐positive bacteria) and Escherichia coli (as Gram‐negative bacteria) were both greater than 15 mm, it demonstrated significant antibacterial activity compared with the ATU‐HPCS gel membranes. The double effects of the biocompatibility of chitosan and the sustained‐release of iodine provided an ideal healing environment for wound surface. These properties have made ATU‐HPCS‐I₂‐M highly potential as a novel natural macromolecule antimicrobial material preventing the bacteria from burns, surgery wounds, etc. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40535.     

Carbohydrate crosslinked biocompatible polyurethanes: Synthesis,characterization, and drug delivery studies

A series of novel polyurethanes (PUs) with carbohydrate crosslinkers was synthesized. The drug loading and release kinetics were studied by using lamotrigine as a model drug. The polymers were designed in such a way that the drug release was tailored by differences in the stoichiometry of polymers. All the PUs were characterized for thermal and morphological properties by using differential scanning calorimetry and thermogravimetric analysis and scanning electron microscope , respectively. The encapsulation of drug inside PU matrix was confirmed via Fourier transform ‐ infrared (FT‐IR) spectra and scanning electron microscope . The kinetics and release mechanisms were observed to be a function of stoichiometric parameters such as type of crosslinker, polyol/crosslinker ratio and polyol/chain extender ratio. All the PUs were observed to be non‐cytotoxic in normal lung cell line L132. The synthesized PUs exhibited good mechanical strength, tunable release rates and biocompatibility that can be utilized in biomedical applications like wound dressing, biomedical implants , and drug delivery carriers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42223.     

Co‐electrospun nanofibers of PVA‐SbQ and Zein for wound healing

In this study, electrospun biocompatible nanofibers with random orientation were prepared by physically blending poly(vinyl alcohol)‐stilbazol quaternized (PVA‐SbQ) with zein in acetic acid solution for wound healing. PVA‐SbQ was used as the foundation polymer as well as crosslinking agent, blended with zein to achieve desirable properties such as improved tensile strength, surface wettability, and in vitro degradable properties. Moreover, vaccarin drug was incorporated in situ into electrospun nanofibrous membranes for cell viability and cell attachment. The addition of vaccarin showed great effects on the morphology of nanofiber and enhanced cell viability and proliferation in comparison with composite nanofibers without drug. The presence of PVA‐SbQ, zein, and vaccarin drug in the nanofibrous membranes exhibited good compatibility, hydrophilicity, and biocompatibility and created a moist environment to have potential application for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42565.