Hydroxypropyl Methylcellulose Films Research Articles

A comparison between solvent casting and electrospinning methods for the fabrication of HPMC fast-dissolving films: investigation of the physicochemical, mechanical and drug release characteristics

The fast-dissolving film is an innovative dosage form that rapidly delivers the loaded drug upon contact with saliva. Many studies have been conducted on the fabrication of fast-dissolving films using hydroxy propyl methyl cellulose (HPMC) as a common film-forming agent with solvent-casting method or sometimes with electrospinning. However, there is no comparison of these two methods on the physicochemical, mechanical, and drug-release behavior of HPMC films. This paper aims to compare bisoprolol-containing fast-dissolving films composed of HPMC and polyethylene glycol (PEG) as plasticizer constructed by solvent-casting and electrospinning methods. Given the formulation parameters (e.g., plasticizer and polymer concentrations) and process parameters (e.g., tip-to-needle distance, voltage, and feed rate), various solvent-casting films and nanofiber mats were prepared. Films were characterized in terms of disintegration time, folding endurance, thermal behavior (using DSC), crystallin structure (using XRD), drug content, and drug release. The size and morphology of nanofibers were also evaluated by SEM. Solvent-casting film composed of 6% w/v HPMC and 6% v/v PEG400, as well as nanofiber mat composed of 13% w/v HPMC and 3% w/v PEG2000 were successfully constructed. DSC and XRD analysis revealed that the crystalline structure of bisoprolol converted into the amorphous structure in the polymeric films. Nanofibers were smooth and free of beads with a mean size of 0.66 ± 0.19 μm. In terms of flexibility, the nanofiber mats outperformed the solvent-casting films. The disintegration time of the nanofiber mat was less than that of the solvent-casting film (3 s versus 30 s). Besides, nanofibers indicated faster release. The superior performance of nanofiber mats can be attributed to their nanostructure. The results showed that the characteristics of the fast-dissolving films fabricated of HPMC, including disintegration time, release rate, and flexibility could be improved through the electrospinning process.

Microbiological and Physicochemical Evaluation of Hydroxypropyl Methylcellulose (HPMC) and Propolis Film Coatings for Cheese Preservation.

Dairy products are highly susceptible to contamination from microorganisms. This study aimed to evaluate the efficacy of hydroxypropyl methylcellulose (HPMC) and propolis film as protective coatings for cheese. For this, microbiological analyses were carried out over the cheese' ripening period, focusing on total mesophilic bacteria, yeasts and moulds, lactic acid bacteria, total coliforms, Escherichia coli, and Enterobacteriaceae. Physicochemical parameters (pH, water activity, colour, phenolic compounds content) were also evaluated. The statistical analysis (conducted using ANOVA and PERMANOVA) showed a significant interaction term between the HPMC film and propolis (factor 1) and storage days (factor 2) with regard to the dependent variables: microbiological and physicochemical parameters. A high level of microbial contamination was identified at the baseline. However, the propolis films were able to reduce the microbial count. Physicochemical parameters also varied with storage time, with no significant differences found for propolis-containing films. Overall, the addition of propolis to the film influenced the cheeses' colour and the quantification of phenolic compounds. Regarding phenolic compounds, their loss was verified during storage, and was more pronounced in films with a higher percentage of propolis. The study also showed that, of the three groups of phenolic compounds (hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids), hydroxycinnamic acids showed the most significant losses. Overall, this study reveals the potential of using HPMC/propolis films as a coating for cheese in terms of microbiological control and the preservation of physicochemical properties.

Enhanced mechanical and antimicrobial properties of hydroxypropyl methylcellulose films incorporating silver nanoparticles for wound dressing applications

Enhanced mechanical and antimicrobial properties of hydroxypropyl methylcellulose films incorporating silver nanoparticles for wound dressing applications

Facile superhydrophobic modification on HPMC film using polydimethylsiloxane and starch granule coatings

The excessive water sensitivity of hydroxypropyl methylcellulose (HPMC) films prevent them from being used extensively. In order to overcome this limitation, superhydrophobic HPMC films were meticulously crafted through the utilization of a composite of polydimethylsiloxane (PDMS) and ball-milled rice starch, corn starch, or potato starch (RS/CS/PS) for the coating process. Initially possessing hydrophilic properties, the HPMC Film (CA = 49.3 ± 1.8°) underwent a transformative hydrophobic conversion upon the application of PDMS, resulting in a static contact angle measuring up to 103.4 ± 2.0°. Notably, the synergistic combination of PDMS-coated HPMC with ball-milled starch demonstrated exceptional superhydrophobic attributes. Particularly, the treated HPMC-based film, specifically the HP-CS-2 h film, showcased an impressive contact angle of 170.5° alongside a minimal sliding angle of 5.2°. The impact of diverse starch types and the ball milling treatment on the PDMS/starch coatings and HPMC film was thoroughly examined using scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXS), and particle size analysis. These studies demonstrated that the low surface energy and roughness required for the creation of superhydrophobic HPMC-based films were imparted by the hierarchical structure formed by the application of PDMS/ball-milled starch. Chemical compounds studied in this articlePolydimethylsiloxane (PubChem CID: 24764); Hydroxypropyl methylcellulose (PubChem CID: 671); Ethyl acetate (PubChem CID: 8857).

Development and characterization of cellulose nanofiber reinforced hydroxypropyl methylcellulose films functionalized with propolis-loaded zein nanoparticles and its application for cheddar cheese storage

Cellulose nanofiber (CNF) reinforced hydroxypropyl methylcellulose (HPMC) films were functionalized with propolis-loaded zein nanoparticles (ZNP) to develop active, printable, and heat-sealable films. The films with 0, 0.10, 0.25, 0.50, or 0.75 mg/mL propolis-loaded ZNP, named 0ZNP, 0.10ZNP, 0.25ZNP, 0.50ZNP, and 0.75ZNP, respectively, were characterized for their mechanical, physicochemical, structural, functional and optical properties and antioxidant activity. The addition of propolis-loaded ZNP did not change tensile strength (P > 0.05), but increased elongation at break (from 24.72 to 36.58 %) (P < 0.05) for 0.25ZNP film. A water contact angle increased significantly (P < 0.05) for 0.50ZNP (~45 %) and 0.75ZNP (~137 %) films. The 0.25ZNP and 0.75ZNP films were evaluated for packaging cheddar cheese under refrigerated storage for 30 days, and resulted in comparable water activity, pH, titratable acidity, and lipid oxidation (P > 0.05) with those packaged by LDPE film and vacuum package. The developed films can function as eco-friendly alternatives to single-use plastic food packaging.

Characterization of Layer-by-Layer Biodegradable Films Based on Hydroxypropyl Methylcellulose-Nanochitosan

This research investigates the physical and optical properties of single-layer and layer-by-layer biodegradable films composed of hydroxypropyl methylcellulose (HPMC) and nanochitosan. Initially, HPMC and nanochitosan were formulated as single layers at various concentrations, and subsequently, the selected formulas were utilized to produce a layer-by-layer film. The results indicate that the concentrations of 0.4% w/v HPMC and 0.5% w/v of nanochitosan were successfully assembled into a layer-by-layer biodegradable film. Assessment based on multiple parameters (thickness, moisture content, water vapor transmission rate, color, transparency, and biodegradability) reveals that the deposition of nanochitosan onto HPMC in a layer-by-layer configuration enhances most characteristics of single-layer HPMC films, with the exception of optical properties. Moreover, all samples were degraded within a seven-day observation period.

Development of hydroxypropyl methylcellulose films with corn silk polysaccharides and its application as biomaterial in enhancing the shelf life of mozzarella cheese

AbstractHydroxypropyl methylcellulose (HPM) is a viscous modified natural polymer that is utilised as thickener, emulsifier and reducer of serum cholesterol. Novel films composed from HPM and corn silk polysaccharides (CSP) were prepared (HPM‐corn silk [CS]). The impact of using different percentages of CSP on the characteristics of HPM‐CS was studied. Results showed that replacing 37.5% of HPM with CSP led to a significant improvement in mechanical properties, with an increase of 58.71% for tensile strength and 54.29% for elongation at break. In addition, the produced films showed improved opacity, antioxidant activities and a smooth, continuous surface without any grooves, as well as being biodegradable. However, the thermal stability was reduced, and the crystallinity shapes were disrupted at higher concentrations due to the inclusion of CSP in the HPM‐CS films. The best HPM concentration (1 g/100 mL) with optimum CSP concentration of (0.6 g/100 mL) was used as food packaging material for low‐moisture mozzarella cheese. The packaging material kept the stability of total microbial count in hygienic scale up to 40 days of cold storage, moisture loss and pH values up to 30 days. Additionally, the results of hedonic sensory evaluation were satisfied compared with fresh cheese until 30 days of storage.

Development and characterization of cinnamon essential oil incorporated active, printable and heat sealable cellulose nanofiber reinforced hydroxypropyl methylcellulose films

Cellulose nanofiber (CNF) reinforced hydroxypropyl methylcellulose (HPMC) films were incorporated with antioxidant cinnamon essential oil (CEO) to develop active, printable, and heat-sealable films. CEO was carried into the films via three types of active systems: β-cyclodextrin (β-CD) encapsulation, cellulose nanocrystal (CNC) Pickering emulsion (CNC-P), or the combination thereof (CNC-P/β-CD). The films were characterized for their mechanical, physicochemical, structural, thermal, and optical properties along with CEO release, printability, and heat seal strength. The Control film (without active CEO) and CNC-P film showed the highest transparency, 17.02% and 18.17%/mm, respectively, followed by the CNC-P/β-CD (12.86%/mm) and β-CD (11.68%/mm) films. A significant difference (P < 0.05) in water vapor permeability (WVP) was observed between the Control film stored at 33% RH (72.01 g mm/m2 d kPa) and 53% RH (54.45 g mm/m2 d kPa) whereas no difference in WVP for β-CD, CNC-P, and CNC-P/β-CD films under RH range of 33–84% (P > 0.05). The presence of active CEO in the films enhanced the moisture barrier and stability of films without influencing the mechanical and thermal properties of the films. The CEO incorporated films via both CNC Pickering emulsion and β-CD encapsulation prolonged the release of CEO. All CEO incorporated films were printable by inkjet and stamp inks and showed good heat seal strength (∼61–73 N/m). This study provided new strategies to develop cellulose-based active films with extended antioxidant function and sealable and printable properties to replace single-use plastic packaging for various food, especially high-fat food items.

The effect of polymeric films of hydroxypropyl methylcellulose (HPMC)/chitosan on ofloxacin release, diffusion, and biological activity

AbstractInfectious diseases caused by resistant bacteria have been investigated by several researchers recently. Ofloxacin is a quinolone antibiotic used against resistant microorganisms and in different routes of administration. Transdermal drug delivery is used to reduce drug toxicity, avoid first‐pass metabolism, and reduce fluctuations in drug concentration in the body. Ofloxacin was formulated in a transdermal polymeric formula using hydroxypropyl methyl cellulose (HPMC) and chitosan at different ratios in the presence of palmitic acid as a permeation enhancer. Physical characterization, drug release and diffusion, drug matrix association, and antimicrobial assay have been investigated using different techniques including HPLC, fourier‐transform infrared spectroscopy (FTIR), Franz cells diffusion, and UV spectroscopy. Ofloxacin release was successfully accomplished in many polymeric formulas containing a high ratio of HPMC with a maximum drug release of 53%. Formulas selected for antimicrobial assay indicate that sustained release patches have successfully inhibited microbial and biofilm growth with a percentage inhibition of more than 90%. In conclusion, antibiotics can be formulated in transdermal polymeric film to target skin infection and reduce drug toxicity and avoid drug first metabolism for drugs reaching systemic circulation which has a direct influence on drug activity.

Extraction and characterization of novel cellulose nanocrystals from Artemisia scoparia straw and their application in hydroxypropyl methyl cellulose (HPMC) films

Abstract This research study reports on the extraction of nanocellulose followed by structural and thermal analysis and application of nanocellulose in hydroxypropyl methyl cellulose (HPMC) nanocomposite films. The cellulose nanocrystals were isolated from Artemisia scoparia straw through an alkaline treatment and bleaching process, followed by sulphuric acid hydrolysis. The HPMC nanocomposite films were prepared by a solution casting method and dried at room temperature. Fourier transform infrared-ray (FTIR) spectroscopy and thermogravimetric analysis (TGA) techniques were used to analyze the structural and thermal properties of the materials, including the cellulosic material, the nanomaterial, and the nanocomposites. The FTIR spectra indicated that the extraction procedure was adequate, demonstrating the removal of lignin and hemicellulose and the preparation of nanocellulose. The TGA results revealed the thermal degradation pattern of the cellulose and showed that the HPMC films had enhanced thermal stability. This research demonstrates that A. scoparia straw has potential for the extraction of cellulosic nanomaterial and a wide range of applications in nanocomposites.

TECHNOLOGY OF HYBRID MODIFICATION WITH HUMIC ACIDS OF BROWN COAL HYDROXYPROPYLMETHYL CELLULOSE FILMS

The peculiarities of the technology of hybrid modification of lignite humic acids of biodegradable films based on hydroxypropylmethylcellulose are considered. As a result of the conducted research, hybrid biodegradable films with antibacterial properties were obtained for the first time. Hydroxypropylmethylcellulose of the Walocel brand was used for the production of biodegradable films, and citric acid (99.88%) according to GOST 3652 is used as a catalyst for crosslinking biodegradable polymer films. As part of the research, the hybrid structures of hydroxypropylmethylcellulose modified with different types of humic acids were actually determined by IR spectroscopy. As a result of the study, the regularities of changes in the time of appearance of mold of films within the framework of the technology of hybrid modification with lignite humic acids were established. It was also established that the technology of hybrid modification of hydroxypropylmethylcellulose films with humic acids of lignite and giving them antibacterial properties allows to preserve the properties of biodegradation. It was established that the technology of hybrid modification of hydroxypropylmethylcellulose with lignite humic acids of biodegradable hydroxypropylmethylcellulose films with different types of humic acids, while giving them antibacterial properties, allows the biodegradation of films based on them to be at least 91% within 6 months with an optimal humic acid content of 10% by mass. Biodegradable films with bactericidal properties based on hydroxypropylmethylcellulose, obtained according to the technology of hybrid modification with humic acids of lignite, in terms of their operational characteristics, are superior to known similar biodegradable films based on natural biopolymers and can be recommended for the manufacture of packaging of dry food products (bread, cereals, nuts, etc.) with an extended storage period.

Effect of adding nano-materials on the properties of hydroxypropyl methylcellulose (HPMC) edible films

The bio-composite films based on Hydroxypropyl methylcellulose (HPMC) reinforced with silver nanoparticles (AgNPs) and Titanium oxide nanoparticles (TiO2-NPs) were developed. Some physical and mechanical properties: Tensile strength (TS), elongation (E), Young’s elastic modulus (EM), water vapor permeability (WVP) and transparency were determined. Antibacterial properties of these films were also studied. The tensile strength values of HPMC film reinforced with Ag NPs and TiO2-NPs and HPMC without nanoparticles were 39.24, 143.87 and 157.92 MPa, respectively. Elongation of the HMPC film was less than the HPMC film reinforced with AgNPs and TiO2-NPs, the results were 2, 35 and 42%, respectively. Additionally, Young’s elastic modulus of HMPC film was determined to be 19.62 MPa and the HPMC film reinforced with AgNPs and TiO2-NPs were 4.11 and 3.76 MPa, respectively. The values of WVP of HMPC film was higher than the HMPC film reinforced with AgNPs and TiO2-NPs, where they were 0.5076 × 10−3, 0.4596 × 10−3 and 0.4504 × 10−3 (g/msPa), respectively. Nano-composite films demonstrated strong antibacterial activity against tested pathogen bacteria in the contact surface zone. The antibacterial activites of AgNPs (~ 10 nm) at 80 ppm were more active than 20 and 40 ppm against foodborne pathogen i.e. Bacillus cereus and Escherichia coli, the inhibition zone diameters were 9 and 10 mm, respectively. As well, TiO2-NPs (~ 50 nm) at 80 ppm were more active than 20 and 40 ppm against B. cereus and Salmonella Typhimurium, the inhibition zone diameters were11 and 10 mm, respectively.

HPMC films functionalized by zein/carboxymethyl tamarind gum stabilized Pickering emulsions: Influence of carboxymethylation degree

Pickering emulsions are promising systems to act as carriers of active hydrophobic components, and to improve compatibility and the water vapor barrier properties of bio-based films. This study aimed to investigated the effects of cinnamon essential oil Pickering emulsions (CEOEs) using zein/carboxymethyl tamarind gum as stabilizers on the mechanical, barrier, antibacterial and antioxidant properties of Hydroxypropyl methyl cellulose (HPMC) films, and assessed the influence of carboxymethylation degree. In addition, the effect of the packaging was studied on the shelf life of cherry tomatoes. Results showed that the droplet size reduced approximately from 93.03 to 10.59 μm with the increasing degree of substitution (DS), greatly facilitating the droplet uniform distribution in film matrix. Moreover, with the addition of CEOEs, significant increase was observed with the tensile strength from 8.46 to 25.41 MPa, and the water vapor permeability decreased from 6.18 × 10−10 to 4.24 × 10−10 g·m−1·s−1·Pa−1. The films exhibited good UV barrier properties without sacrificing the transparency after adding CEO. Furthermore, the antibacterial and antioxidant activities of the prepared films have also been greatly improved. Consequently, the CEOEs was an ideal alternative for incorporation with HPMC based films for increasing the shelf life of cherry tomatoes.

Improved hydroxypropyl methylcellulose films through incorporation of amylose-N-1-hexadecylammonium chloride inclusion complexes

In order to replace petroleum based films used in food packaging, improved biobased options are needed. Hydroxypropyl methylcellulose (HPMC) has value, but in terms of oxygen and water vapor permeability it is deficient. Blended films were produced using HPMC and amylose-N-1-hexadecylammonium chloride inclusion complex (HexAM) that required no plasticizer. The resulting blended films were clear, had little color and had increased product value relative to the control. With the addition of the HexAM, the crystallinity of the film increased as seen by x-ray diffraction spectra. By SEM the surfaces of the films were relatively smooth by scanning electron microscopy. However, atomic force microscopy demonstrated that the control films were smoother (roughness 1.2 nm rms), relative to the 50 % HexAM blend films (roughness 29.9 nm rms). In the infrared spectra (IR) certain peaks, such as the hydrated water and glycosidic bond peaks, either increased or decreased in a liner fashion with incorporation of HexAM. Using microscopic IR, it was shown that the surfaces of the films were chemically homogeneous on a 1.56 µm scale. Tensile strength and elongation decreased slightly with increasing HexAM. However, increasing the HexAM provided increased thermal durability as evidenced by a reduction in the loss of modulus with heating. This attribute will have value in the market. The addition of HexAM decreased the permeation of oxygen and water vapor through the films and made the film surface more hydrophobic. These characteristics will resolve deficiencies in HPMC and allow it to enter new markets. In limited testing, the HexAM containing films provided microbial and thermal resistance. For control HPMC films, gas permeability, water sensitivity and poor thermal stability limit the applications of HPMC.

Rheology of nano ZnO - Hydroxypropyl Methylcellulose (HPMC) based suspensions and structural properties of resulting films

Effect of polyethylene glycol (PEG) and ZnO nanoparticles concentration on rheological properties of the hydroxypropyl methylcellulose (HPMC) based film forming suspensions (FFS) and, on the structural properties of the resulting films were characterized. Rheological properties of FFS were not significantly affected by PEG concentration and ZnO NPs incorporation. Intrinsic viscosity [η] of aqueous HPMC solution obtained from extrapolation of Huggins and Kraemer plot was 0.115–0.118 (L/g). Coating thickness calculated as a function of coating solution viscosity, concentration and draining time for strawberry coating was 1.26–1.49 μm. Tensile strength (TS) of HPMC film decreased while water vapour permeability (WVP) increased with increasing PEG concentration. Elongation at break (%E) increased up to 25% PEG concentration and decreased afterward. Incorporation of ZnO NPs improved the tensile strength and barrier properties of HPMC film. Relaxation percentage and stress decay rate increased with increasing plasticizer concentration while decreased with incorporation of ZnO NPs. • Rheological behaviour of aqueous HPMC solution (4% w/v) was Newtonian. • Calculated Intrinsic viscosity [η] of aqueous HPMC solution was 0.115–0.118 (L/g). • Relaxation % and stress decay rate showed positive correlation with PEG concentration. • Added ZnO nanoparticles improves the HPMC film properties.

High viscosity hydroxypropyl methyl cellulose to improve inkjet printing for cotton/polyamide fabrics

When dyes were used for inkjet printing on multi-component fabrics, the complex acid-base conditions, high temperature and high humidity posed a challenge to the stability of water-soluble polymers covered the surface of the fabrics. In this study, hydroxypropyl methyl cellulose (HPMC) was used to construct a continuous film on the surface of cotton/polyamide interwoven fabric. The results show that the formation of ridges between fibers is closely related to the properties of HPMC. Fibers in the yarn were connected to each other by HPMC, which prevented inks from penetrating into the bottom of the yarns. Meanwhile, HPMC maintained high viscosity under acidic conditions, which provided conditions for reactive dyes to dye polyamide fibers under acidic conditions. Compare with sodium alginate, the color depth of cyan, magenta, yellow and black improved by 75.1 %, 101.8 %, 181.3 %, 207.5 % on cotton/polyamide fabrics using HPMC, separately. Hydroxypropyl methyl cellulose is effective to improve inkjet printing for cotton and polyamide fiber, which has the possibility of widespread application in natural fiber and synthetic fiber. • Hydroxypropyl methyl cellulose membrane is constructed to connect adjacent fibers. • The formation of ridge structure is due to the high viscosity of HPMC solution. • The ink penetration is constrained along the direction perpendicular to the fabric. • The inkjet printing effect of C/PA fabric is improved with the help of HPMC film.

Chitosan for eco-friendly control of mycotoxinogenic Fusarium graminearum

This work explores the use of chitosan as an active matrix to develop biofungicides. Two chitosans from marine resources, of 4.8 and 78 kg/mol respectively, were structurally characterized. Both chitosans diluted in acidic conditions (lactic or acetic acid at 1%, v/v) were efficient in reducing the growth of Fusarium graminearum. Ammonium groups of chitosan chains were suggested as key determinants for the polysaccharide's activity. The chitosan of 78 kg/mol was also efficient in decreasing the production of mycotoxins by F. graminearum leading to an inhibition rate of 70%. Moreover, the film forming properties of the 78 kg/mol chitosan were physicochemically characterized and used to mimic how the bioformulation should look when sprayed on the plant. Interestingly, the film was proved to totally inhibit the mycelium growth, contrary to a hydroxypropylmethyl cellulose film, an electrically-neutral analogue to our biopolymeric coating of chitosan.

Rheological and optical response of hydroxypropyl methylcellulose under variable temperatures for optical switching based on thermo‐optical effect

AbstractThis work is devoted to investigate novel aspects of the rheological and optical response of hydroxypropyl methylcellulose (HPMC) as a result of temperature variations from 308.15 to 338.15 K. First, new insights on correlation between the solution flow behavior and the film thickness uniformity, under distinct temperatures, are established. Then, the HPMC film is examined from the point of view of some basic surface parameters describing the surface morphology, such as root mean square roughness, surface area ratio, texture direction index, kurtosis, skewness and surface bearing index. The refraction properties of HPMC are reported for the first time as a function of wavelength and temperature. The changes in the optical dispersion parameters as a function of temperature increase reveal the reduction of strength of interband optical transitions from 15.147 to 14.086 eV and a smaller band gap from 6.475 to 6.137 eV. The latter is caused by temperature‐induced dilatation of the polymer lattice and its effect on the electron–lattice interactions. The thermo‐optic coefficient of HPMC is found to be larger than that of other polymers, while its dependence on the wavelength is small, varying from −2.03 × 10−4 K−1 at 489 nm to −2.31 × 10−4 K−1. The resulted properties are corresponding to the demands imposed for materials used in optical switching based on thermo‐optical effect.

Hydroxypropyl methylcellulose-based films incorporated with Ocimum basilicum L. extract for skin wound healing

The skin acts as a protective barrier for the body. Significant functional limitations can occur when damaged, such as pain and infections. This study aims to develop hydroxypropyl methylcellulose (HPMC) films incorporated with Ocimum basilicum L. (OB) extract for wound healing. The plant extract was prepared, followed by production and morphological evaluation of the films determining, for example, water vapor transmission, swelling index, solubility, and antioxidant activity. The films were macroscopically homogeneous, transparent, flexible, and resistant, with an average thickness of 157 μm. They also showed high hydrophilicity due to the polarity of the polymer, soluble in aqueous media, with a good degree of swelling (1.254 % for HPMC + OB 15 %) and good permeability to water vapor (1.467% for the control film), with a light decrease after incorporation of the extract. However, adding the extract increased the antioxidant activity significantly, around 50%, compared to the control film. Thus, it proves to be a promising dressing for wound healing due to the good physical characteristics of the polymer, combined with the antioxidant activity of the extract.

Hydroxypropyl methylcellulose/carboxymethyl starch/zinc oxide porous nanocomposite films for wound dressing application

Because of low moisture uptake, water vapor transmission rate, oxygen transmission rate, swelling capacity and no antibacterial activity of hydroxypropyl methylcellulose (HPMC) film, carboxymethyl starch (CMS) and zinc oxide nanoparticles (ZnO-NPs) were incorporated in order to improve its limitations for wound dressing application. The infrared shifted peak of OH stretching and OH bending in HPMC/CMS blended films was detected due to hydrogen bond formation between HPMC and CMS. Scanning electron images of HPMC/CMS blended films exhibited porous structure. In addition, swelling degree, moisture uptake, water vapor transmission rate and oxygen transmission rate of HPMC/CMS blended films with various contents of CMS clearly increased compared to HPMC film. Moreover, HPMC/CMS nanocomposite films loaded with ZnO-NPs showed good antibacterial activity against Staphylococcus aureus and Escherichia coli, revealing their potential for wound dressing application. Percentage of crystallinity, cytotoxicity, mechanical and thermal properties were also examined.