Application of hydroxypropyl methylcellulose to improve the wettability of chitosan coating and its preservation performance on tangerine fruits.

Hydroxypropyl methylcellulose (HPMC) was employed as an intermediate layer to enhance interfacial interaction between chitosan (CS) coating and tangerine fruits, thereby improving the preservation effect. Owing to the low surface tension of tangerine fruit (26.04 mN/m), CS coating solutions showed poor wetting properties on fruit peels (contact angle > 100°). However, by applying a 1.0 % (w/v) HPMC coating on fruits, the contact angle of CS solutions with concentrations of 0.5 %, 1.0 %, and 1.5 % (w/v) decreased to 47.0°, 47.4°, and 48.5°, respectively, whereas the spreading coefficient increased to -16.0 mN/m, -17.6 mN/m and -19.8 mN/m, respectively. Subsequently, the effects of the coatings on fruit quality were investigated. The results demonstrated the promising performance of HPMC-CS two-layer coating in inhibiting fruit respiration, reducing decay rate, and maintaining nutrient content. Notably, HPMC-1.5%CS coating not only reduced the decay rate of tangerine fruit by 45 % and 31 %, in comparison to the uncoated group (CK) and pure CS coating respectively, but also maintained a high content of ascorbic acid. Therefore, this study confirmed that the use of amphiphilic polymers for improving the surface properties of fruits can effectively facilitate the wetting of hydrophilic coatings on fruits, and significantly improve the fresh-keeping performance of edible coatings.

Co-release of paclitaxel and encequidar from amorphous solid dispersions increase oral paclitaxel bioavailability in rats.

The oral bioavailability of paclitaxel is limited due to low solubility and high affinity for the P-glycoprotein (P-gp) efflux transporter. Here we hypothesized that maximizing the intestinal paclitaxel levels through apparent solubility enhancement and controlling thesimultaneous release of both paclitaxel and the P-gp inhibitor encequidar from amorphous solid dispersions (ASDs) would increase the oral bioavailability of paclitaxel. ASDs of paclitaxel and encequidar in polyvinylpyrrolidone K30 (PVP-K30), hydroxypropylmethylcellulose 5 (HPMC-5), and hydroxypropylmethylcellulose 4 K (HPMC-4K) were hence prepared by freeze-drying. In vitro dissolution studies showed that both compounds were released fastest from PVP-K30, then from HPMC-5, and slowest from HPMC-4K ASDs. The dissolution of paclitaxel from all polymers resulted in stable concentration levels above the apparent solubility. The pharmacokinetics of paclitaxel after oral administration to male Sprague-Dawley rats was investigated with or without 1 mg/kg encequidar, as amorphous solids or polymer-based ASDs. The bioavailability of paclitaxel increased 3- to 4-fold when administered as polymer-based ASDs relative to solid amorphous paclitaxel. However, when amorphous paclitaxel was co-administered with encequidar, either as an amorphous powder or as a polymer-based ASD, the bioavailability increased 2- to 4-fold, respectively. Interestingly, a noticeable increase in paclitaxel bioavailability of 24-fold was observed when paclitaxel and encequidar were co-administered as HPMC-5-based ASDs. We, therefore, suggest that controlling the dissolution rate of paclitaxel and encequidar in order to obtain simultaneous and timed release from polymer-based ASDs is a strategy to increase oral paclitaxel bioavailability.

Evaluation of the printability of agar and hydroxypropyl methylcellulose gels as gummy formulations: Insights from rheological properties.

The trial-and-error method currently used to create formulations with excellent printability demands considerable time and resources, primarily due to the increasing number of variables involved. Rheology serves as a relatively rapid and highly beneficial method for assessing materials and evaluating their effectiveness as 3D constructs. However, the data obtained can be overwhelming, especially for users lacking experience in this field. This study examined the rheological properties of formulations of agar, hydroxypropyl methylcellulose, and the model drug caffeine, alongside exploring their printability as gummy formulations. The gels' rheological properties were characterized using oscillatory and rotational experiments. The correlation between these gels' rheological properties and their printability was established, and three clusters were formed based on the rheological properties and printability of the samples using principal component analysis. Furthermore, the printability was predicted using the sample's rheological property that correlated most with printability, the phase angle δ, and the regression models resulted in an accuracy of over 80%. Although these relationships merit confirmation in later studies, this study suggests a quantitative definition of the relationship between printability and one rheological property and can be used for the development of formulations destined for extrusion 3D printing.

Efficacy and Safety of Artificial Tears Containing Lipidure and Hypromellose for the Treatment of Moderate Dry Eye Disease in Contact Lens Wearers.

Background and Objectives: Dry eye disease (DED) affects 5-50% of the global population and deeply influences everyday life activities. This study compared the efficacy, tolerability, and safety of novel Respilac artificial tears containing lipidure and hypromellose (HPMC) with the widely used Nextal artificial tears, which are also HPMC-based, for the treatment of moderate DED in contact lenses (CL) wearers. Materials and Methods: In a prospective, single-center, randomized investigation, 30 patients aged ≥18 years, diagnosed with moderate DED, and wearing CL were randomly assigned to the Respilac (n = 15) or Nextal group (n = 15). Patients self-administrated one drop of Respilac or Nextal in both eyes three times daily for 21 days. Changes in the endpoint (visual analogue scale (VAS) score for ocular tolerability, symptom assessment in dry eye (SANDE) score, non-invasive first break-up time (NIF-BUT) results, tear analysis value, meibography results, and CL tolerability results were assessed, comparing treatment groups and time-point evaluations. Adverse events (AEs) were also recorded and evaluated. Results: VAS scores decreased with time (p < 0.001) in both groups, showing no statistically significant difference among them (p = 0.13). Improvements were also detected from screening to end-of-treatment, which were indicated by the SANDE scores for severity and frequency (p < 0.001) and by tear analysis results (p < 0.001) with no observed difference between the Nextal and Respilac arms. NIF-BUT, meibography, and CL tolerability values were shown to be non-significantly affected by treatment and time. There were no AEs detected in this study cohort. Conclusions: Respilac was confirmed to be effective, safe, and well-tolerated. Lipidure-based ophthalmic solution was shown not to be inferior to the currently used Nextal, however, showing improvements in DED symptoms. Within the existing literature, our study is one of the first to report that MPC plus HPMC-containing eye drops are an effective option for the treatment of moderate dry eye disease and desiccation damage prevention in contact lens wearers.

Heat-triggered shape recovery, EMI shielding and flame retardant: A novel cellulose/M(OH)(OCH3)@dopamine@Ag (M=Co, Ni) nanopaper for early fire alarm.

Fire alarm systems are essential for protecting lives and properties from fire hazards. However, most of the existing fire alarm nanopapers rely on the resistance reduction after heating, which requires direct contact with the flame. In this study, we present a novel fire alarm nanopaper (CMPA) based on heat-triggered shape recovery. The CMPA is composed of hydroxypropyl methyl cellulose (HPMC) as the matrix and 2D nanomaterials M(OH)(OCH3) as fillers. When the temperature of CMPA exceeded the glass transition, the thrice-folded CMPA-1.0 flattened in 30s and connected to the alarm circuit based on its conductive surface. According to the results, the CMPA-1.0 with a thickness of about 0.2 mm had an efficient electromagnetic shielding of 42.1 dB. Moreover, the CMPA-1.0 self-extinguished rapidly after being ignited with its original shape preserved. The peak heat release rate of CMPA-1.0 was 108.9 W/g, which was 61.9 % lower than that of HPMC. Furthermore, the thermal conductivity of CMPA-1.0 reached to 0.317 W m-1 K-1, which was 40.8 % higher than that of HPMC, reducing the heat accumulation effectively. This work shows that CMPA is an ideal material for sensitive and safe early fire alarm, and the strategy based on heat-triggered shape recovery is promising in fire alarm application.

Development of nanostructured environmentally responsive system containing hydroxypropyl methylcellulose for nose-to-brain administration of meloxicam.

The intranasal administration of drugs using environmentally responsive formulations, employing a combination of hydroxypropyl methylcellulose (HPMC) and poloxamer 407 (P407), can result in release systems that may assist in the treatment of neurological diseases. Meloxicam, considered a potential adjuvant in the treatment of Alzheimer's disease, could be used in these platforms. The aim of this work was to develop a mucoadhesive, thermoresponsive, and nanostructured system containing HPMC for nose-to-brain administration of meloxicam. The initially selected systems were investigated for their rheological, mechanical, and micellar size characteristics. The systems were dilatant at 25 °C and pseudoplastic with a yield value at 37 °C, showing viscoelastic properties at both temperatures. The platform containing HPMC (0.1%, w/w) and P407 (17.5%, w/w) was selected and demonstrated good mucoadhesive properties, along with an appropriate in vitro release profile. HPMC could form a binary system with P407, displaying superior mucoadhesive and thermoresponsive properties for nose-to-brain meloxicam administration, indicating that the selected formulation is worthy of clinical studies.

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.

Effect of hydroxypropyl methylcellulose (HPMC) hard capsules on in vitro rumen fermentation kinetics of commonly used feeds in ruminant feeding.

BACKGROUND: Accurate dosing of feed additives is often required to evaluate their effects on rumen fermentation. This can be done using soluble but nonfermentable hydroxypropyl methylcellulose (HPMC) hard capsules. OBJECTIVES: The aim of the study was to evaluate the effect of HPMC hard capsules on the extent and rate of in vitro gas production in eleven feeds. METHODS: Six high-fibre feeds and five concentrates, were weighed into syringes either directly or into HPMC capsules and incubated anaerobically in 30 mL buffered rumen fluid at 39°C. Data obtained from gas production measurements were fitted using the Gompertz model to obtain kinetic parameters for gas production. RESULTS: HPMC hard capsules had no effect on the gas production of the blank sample and concentrate feeds. In contrast, high-fibre feeds weighed in HPMC showed a significant decrease (p < 0.05) in total gas production and gas produced within 24 h of incubation. CONCLUSIONS: The use of HPMC hard capsules was found to be inappropriate for determining gas production kinetics because fermentation subsides at a certain point when peak fermentation is reached (at TMFR), resulting in a decrease in both total potential gas production and gas production within 24 h of incubation. This is particularly evident when high-fibre feeds are incubated.

Highly Stretchable, Fast Self-Healing, Self-Adhesive, and Strain-Sensitive Wearable Sensor Based on Ionic Conductive Hydrogels.

Conductive hydrogels integrate the conductive performance and soft nature, which is like that of human skin. Thus, they are more suitable for the preparation of wearable human-motion sensors. Nevertheless, the integration of outstanding multiple functionalities, such as stretchability, toughness, biocompatibility, self-healing, adhesion, strain sensitivity, and durability, by a simple way is still a huge challenge. Herein, we have developed a multifunctional chitosan/oxidized hyaluronic acid/hydroxypropyl methylcellulose/poly(acrylic acid)/tannic acid/Al3+ hydrogel (CS/OHA/HPMC/PAA/TA/Al3+) by using a two-step method with hydroxypropyl methylcellulose (HPMC), acrylic acid (AA), tannic acid (TA), chitosan (CS), oxidized hyaluronic acid (OHA), and aluminum chloride hexahydrate (AlCl3·6H2O). Due to the synergistic effect of dynamic imine bonds between CS and OHA, dynamic metal coordination bonds between Al3+ and -COOH and/or TA as well as reversible hydrogen, the hydrogel showed excellent tensile property (elongation at break of 3168%) and desirable toughness (0.79 MJ/m3). The mechanical self-healing efficiency can reach 95.5% at 30 min, and the conductivity can recover in 5.2 s at room temperature without stimulation. The favorable attribute of high transparency (98.5% transmittance) facilitates the transmission of the optical signal and enables visualization of the sensor. It also shows good adhesiveness to various materials and is easy to peel off without residue. The resistance of the hydrogel-based sensors shows good electrical conductivity (2.33 S m-1), good durability, high sensing sensitivity (GF value of 4.12 under 1600% strain), low detection limit (less than 1%), and short response/recovery time (0.54/0.31 s). It adhered to human skin and monitored human movements such as the bending movements of joints, swallowing, and speaking successfully. Therefore, the obtained multifunctional conductive hydrogel has great potential applications in wearable strain sensors.

A novel designed nanofibrous mat based on hydroxypropyl methyl cellulose incorporating mango peel extract for potential use in wound care system.

Skin tissue is damaged by factors such as burns, physical injuries and diseases namely diabetes. Infection and non-healing of burn wounds and lack of angiogenesis in diabetic wounds lead to extensive injuries and death. Therefore, the design of wound dressings with antibacterial and restorative capabilities is very important. In this study, nanofibers (NFs) including polyurethane (PU) and hydroxypropyl methyl cellulose (HPMC) were prepared with different ratios and Mango peel extract (MPE) loaded into NFs by electrospinning method. The morphology, chemical structure, porosity, degradation, water vapor permeability, mechanical properties, wettability, antioxidant activity and some cell studies and evaluation of their antibacterial properties were investigated. The optimal mat (PU90/HPMC10) had a defect-free morphology with homogeneous NFs. Furthermore, it showed improved biodegradability, water vapor permeability and porosity compared to other Mats. All NFs were non-toxic with hydrophilic behavior in the cellular environment and had acceptable hemocompatibility. The PU90/HPMC10/20 % optimal scaffold had significantly higher cell viability and proliferation than other samples and also had a higher antibacterial ability against pathogenic bacteria S. aureus (17 mm) and E. coli (11 mm). All these findings confirm that the produced NF mats, especially those loaded with MPE, have a high potential to be used as an effective wound dressing.

Dess-Martin oxidation of hydroxypropyl and hydroxyethyl cellulose, and exploration of their polysaccharide/polypeptide hydrogels.

Oxidation of polysaccharides can provide biomaterials with aldehyde and ketone functional groups, which are particularly useful in biomedical applications, like drug delivery, tissue adhesion and hydrogel preparation. However, despite their potential, only a few such methods have been reported, and achieving selective, quantitative oxidation of polysaccharides remains challenging. Herein we report utilization of a mild oxidant, Dess-Martin periodinane, for the chemoselective oxidation of hydroxypropyl cellulose (HPC) and hydroxyethyl cellulose (HEC). Our findings reveal that the oxidation of HPC is fast, efficient and achieves near-quantitative conversion. Moreover, both Ox-HPC and Ox-HEC exhibit low cell toxicity, and readily form hydrogels by reaction with a polypeptide comprising amino acids with amine-containing a-substituents, α-poly-l-lysine. The peptide/polysaccharide hydrogels display self-healing properties, injectability, and antimicrobial activity, making them highly attractive for biomedical applications including in wound dressings.

Changes in Tablet Color Due to Light Irradiation: Photodegradation of the Coating Polymer, Hypromellose, by Titanium Dioxide.

The color of the tablets and capsules produced by pharmaceutical companies is important from the perspectives of product branding and counterfeiting. According to some studies, light can change tablet color during storage. In this study, tablets comprising amlodipine besylate (AB), a well-known light-sensitive drug, were coated with commonly used coating materials and exposed to light. Compared to the tablets that were not exposed to light, the color of those exposed to light changed over time. In fact, a faster and more pronounced color change was observed in the tablets exposed to light; however, the amount of AB did not decrease significantly in these tablets. The coating materials and their amounts were varied to clarify the materials involved in the color change. Based on the results, titanium dioxide and hypromellose may be involved in the color change process. As titanium dioxide is a photocatalyst, it may induce or promote chemical changes in hypromellose upon light irradiation. Overall, care should be exercised during selection of the coating polymer because titanium dioxide may promote photodegradation of the coatings while protecting the tablet's active ingredient from light.

Resveratrol-loaded octenyl succinic anhydride modified starch emulsions and hydroxypropyl methylcellulose (HPMC) microparticles: Cytotoxicity and antioxidant bioactivity assessment after in vitro digestion.

Hydroxypropyl methylcellulose (HPMC)-based microparticles and modified starch emulsions (OSA-MS) were loaded with resveratrol and characterized regarding their physicochemical and thermal properties. Both delivery systems were subject to an in vitro gastrointestinal digestion to assess the bioaccessibility of resveratrol. In addition, cell-based studies were conducted after in vitro digestion and cytotoxicity and oxidative stress were assessed. HPMC-based microparticles displayed higher average sizes (d) and lower polydispersity index (PDI) (d = 948 nm, PDI < 0.2) when compared to OSA-MS-based emulsions (d = 217 nm, PDI < 0.3). Both proved to protect resveratrol under digestive conditions, leading to an increase in bioaccessibility. Resveratrol-loaded HPMC-microparticles showed a higher bioaccessibility (56.7 %) than resveratrol-loaded emulsions (19.7 %). Digested samples were tested in differentiated co-cultures of Caco-2 and HT29-MTX, aiming at assessing cytotoxicity and oxidative stress, and a lack of cytotoxicity was observed for all samples. Results displayed an increasing antioxidant activity, with 1.6-fold and 1.4-fold increases over the antioxidant activity of free resveratrol, for HPMC-microparticles and OSA-MS nanoemulsions, respectively. Our results offer insight into physiological relevancy due to assessment post-digestion and highlight the protection that the use of micro-nano delivery systems can confer to resveratrol and their potential to be used as functional food ingredients capable of providing antioxidant benefits upon consumption.

Preparation of hydroxypropyl methylcellulose/pueraria-based modified atmosphere film and its influence on delaying the senescent process of postharvest Agaricus bisporus.

Based on the key factor of spontaneous modified atmosphere packaging (MAP)-gas permeability, a spontaneous MAP film was created for the preservation of Agaricus bisporus by delaying the senescence of white mushrooms. Compared with other mixed films, hydroxypropyl methylcellulose (HPMC)/pueraria (P)-2 showed better mechanical properties, barrier properties and thermal stability energy. Applying the HPMC/P-2 film for preserving white mushrooms can spontaneously adjust the internal gas environment. Moreover, the O2 concentration in the package remained stable at 1-2 %, and the CO2 concentration was between 8 % and 14 %. The film can effectively reduce the respiration rate of white mushrooms, inhibit enzymatic browning, maintain their good color and texture, and delay their aging. In conclusion, the HPMC/P-2 film can be used not only for fruit and vegetables preservation but also provide theoretical basis for sustainable food packaging.

An antibacterial and anti-oxidant hydrogel containing hyperbranched poly-l-lysine and tea polyphenols accelerates healing of infected wound.

Both bacteria-infection and excessive inflammation delay the wound healing process and even create non-healing wound, thus it is highly desirable to endow the wound dressing with bactericidal and anti-oxidation properties. Herein an antibacterial and antioxidation hydrogel based on Carbomer 940 (CBM) and hydroxypropyl methyl cellulose (HPMC) loaded with tea polyphenols (TP) and hyperbranched poly-l-lysine (HBPL) was designed and fabricated. The hydrogel killed 99.9 % of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) at 107 CFU mL-1, and showed strong antioxidation against H2O2 and 2,2-di(4-tert-octylphenyl)-1-picryl-hydrazyl (DPPH) radicals without noticeable cytotoxicity in vitro. The CBM/HPMC/HBPL/TP hydrogel significantly shortened the inflammatory period of the MRSA-infected full-thickness skin wound of rats in vivo, with 2 orders of lower MRSA colonies compared with the blank control, and promoted the wound closure especially at the earlier stage. The inflammation was suppressed and the vascularization was promoted significantly as well, resulting in reduced pro-inflammatory factors including interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), and increased anti-inflammatory factors such as interleukin-4 (IL-4) and interleukin-10 (IL-10).

The wound healing effect of polycaprolactone-chitosan scaffold coated with a gel containing Zataria multiflora Boiss. volatile oil nanoemulsions.

AIMS: Thymus plant is a very useful herbal medicine with various properties such as anti-inflammatory and antibacterial. Therefore, the properties of this plant have made this drug a suitable candidate for wound healing. In this study, hydroxypropyl methylcellulose (HPMC) gel containing Zataria multiflora volatile oil nanoemulsion (neZM) along with polycaprolactone/chitosan (PCL-CS) nanofibrous scaffold was used, and the effect of three experimental groups on the wound healing process was evaluated. The first group, HPMC gel containing neZM, the second group, PCL-CS nanofibers, and the third group, HPMC gel containing neZM and bandaged with PCL-CS nanofibers (PCL-CS/neZM). Wounds bandaged with common sterile gas were considered as control. METHODS: The nanoemulsion was synthesized by a spontaneous method and loaded into a hydroxypropyl methylcellulose (HPMC) gel. The DLS test investigated the size of these nanoemulsions. A PCL-CS nanofibrous scaffold was also synthesized by electrospinning method then SEM and contact angle tests investigated morphology and hydrophilicity/hydrophobicity of its surface. The animal study was performed on full-thickness skin wounds in rats, and the process of tissue regeneration in the experimental and control groups was evaluated by H&E and Masson's trichrome staining. RESULTS: The results showed that the nanoemulsion has a size of 225±9 nm and has an acceptable dispersion. The PCL-CS nanofibers synthesized by the electrospinning method also show non-beaded smooth fibers and due to the presence of chitosan with hydrophilic properties, have higher surface hydrophobicity than PCL fibers. The wound healing results show that the PCL-CS/neZM group significantly reduced the wound size compared to the other groups on the 7th, 14th, and 21st days. The histological results also show that the PCL-CS/neZM group could significantly reduce the parameters of edema, inflammation, and vascularity and increase the parameters of fibrosis, re-epithelialization, and collagen deposition compared to other groups on day 21. CONCLUSION: The results of this study show that the PCL-CS/neZM treatment can effectively improve wound healing.

Remineralizing effects of hydroxypropyl methylcellulose film-loaded amorphous calcium phosphate nanoprecursors on enamel artificial caries lesions.

OBJECTIVES: This study was to investigate hydroxypropyl methylcellulose (HPMC) film as a carrier for amorphous fluorinated calcium phosphate (AFCP) nanoprecursors to continuously deliver biomimetic remineralization of enamel artificial caries lesions (ACL). MATERIALS AND METHODS: The AFCP/HPMC films were comprised of 25 wt% AFCP nanoparticles and 75 wt% HPMC. They were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and biocompatibility tests. Forty enamel ACL were prepared and randomly divided into four groups (n = 10): The enamel surfaces were covered with a pure HPMC film, Tooth Mousse Plus (contains 10% CPP-ACP and 0.2% NaF), and AFCP/HPMC film, or without any things (serving as negative control). Subsequently, all samples were alternatively kept in artificial saliva and a modified pH-cycling before they were characterized by Micro-CT, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflectance (ATR)-FTIR, XRD, and nanoindentation. RESULTS: After the enamel ACL was challenged by pH cycling, Tooth Mousse Plus and AFCP/HPMC film groups exhibited less lesion depth and mineral loss than the negative control and pure HPMC film groups. Additionally, the AFCP/HPMC film group revealed a highest remineralization rate of 55.34 ± 3.10 % among the all groups (p < 0.001). The SEM findings showed that the enamel ACL were densely deposited with minerals in the AFCP/HPMC film group, and the EDX results suggested a higher content of fluorine in the remineralized tissues. In particular, the AFCP/HPMC film group exhibited the best nanomechanical performance after 2 weeks of pH cycling (p < 0.05), with the hardness (H) restored from 0.29 ± 0.19 to 2.69 ± 0.70 GPa, and elastic modulus (Er) restored from 10.77 ± 5.30 to 68.83 ± 12.72 GPa. CONCLUSION: The AFCP/HPMC film might be used as a promising strategy for arresting or reversing incipient enamel caries lesions.

Photodynamic antibacterial application of TiO2/curcumin/hydroxypropyl-cyclodextrin and its konjac glucomannan composite films.

Although photodynamic therapy (PDT) has great advantages for the treatment of bacterial infections, photosensitizers (PSs) often have many disadvantages that limit their application. Improving the shortcomings of PSs and developing efficient PDT antimicrobial materials remain serious challenges. In this study, a nanocomposite drug (TiO2/curcumin/hydroxypropyl-cyclodextrin, TiO2/Cur/HPCD) was constructed and combined with konjac glucomannan to form composite films (TiO2/Cur/HPCD films, KTCHD films). The stabilities of TiO2 and Cur were improved in the presence of HPCD. The particle size of TiO2/Cur/HPCD was approximately 33.9 nm, and the addition of TiO2/Cur/HPCD enhanced the mechanical properties of the films. Furthermore, TiO2/Cur/HPCD and KTCHD films exhibited good biocompatibility and PDT antibacterial effects. The antibacterial rate of TiO2/Cur/HPCD was 74.46 % against MRSA at 500 µg/mL and 99.998 % against E. coli at 400 µg/mL, while it was adsorbed on the surface of bacteria to improve the effectiveness of the treatment. In addition, studies in mice confirmed that TiO2/Cur/HPCD and KTCHD films can treat bacterial infections and promote wound healing, with a highest wound healing rate of 84.6 % in the KTCHD-10 films + Light group on day 12. Overall, TiO2/Cur/HPCD is a promising nano-antibacterial agent and KTCHD films have the potential to be employed as antibacterial and environment-friendly trauma dressings.

Accelerated corneal crosslinking with 20'-soaking hydroxypropyl methyl cellulose/riboflavin vs conventional crosslinking with 30'-soaking dextran/riboflavin.

PURPOSE: To evaluate and compare functional and structural outcomes of accelerated corneal crosslinking (A-CXL) using riboflavin with hydroxypropyl methyl cellulose (HPMC) vs conventional corneal crosslinking (C-CXL) using riboflavin with dextran. SETTING: American University of Beirut Medical Center, Beirut, Lebanon. DESIGN: Retrospective analysis. METHODS: Retrospective analysis of 83 eyes of 73 patients with mild to moderate keratoconus. First group (n = 44 eyes) underwent C-CXL using a 30-minute riboflavin/dextran soaking between June 2014 and March 2016. Second group (n = 39 eyes) underwent A-CXL using a 20-minute riboflavin/HPMC soaking between April 2016 and December 2017. Patients were evaluated preoperatively and at 1, 3, and 12 months postoperatively. Main outcome measures were simulated keratometry (simK), maximum axial keratometry (Kmax), demarcation line depth, and haze intensity measured using optical coherence tomography-based image analysis software. RESULTS: Demarcation line (DL) was 298.30 ± 64.60 µm and 335.61 ± 99.76 µm for C-CXL and A-CXL groups, respectively ( P = .04). Haze profile was similar for both groups. The mean simK values were reduced from 46.93 ± 3.50 and 46.44 ± 2.93 preoperatively to 46.18 ± 3.65 and 45.54 ± 2.78 at 12 months postoperatively, for C-CXL and A-CXL, respectively ( P = .003 for both groups). The mean Kmax decreased from 52.46 ± 4.82 and 51.50 ± 3.87 preoperatively to 51.30 ± 4.42 and 50.30 ± 3.52 postoperatively, for the C-CXL and A-CXL, respectively ( P < .001 for both groups). There was no difference in the simK and Kmax changes between the C-CXL and A-CXL groups ( P = .814 and P = .913), visual acuity, and refraction between the 2 groups ( P > .05). CONCLUSIONS: A-CXL with a 20-minute riboflavin/HPMC soaking produced deeper DL and similar corneal haze, topographic, refractive, and visual results to C-CXL with a 30-minute riboflavin/dextran soaking.

Potential application of hydroxypropyl methylcellulose/shellac embedded with graphene oxide/TiO2-Nps as natural packaging film.

Graphene oxide (GO), TiO2-NPs, HPMC, and shellac are environmentally green polymers and nanocomposites. This work aimed to create biodegradable composite films made of HPMC/shellac, HPMC/shellac-GO, and HPMC/shellac-GO/TiO2-NPs by film casting. TiO2-HPMC/shellac-GO matrix's dispersibility and mixing ability were characterized and observed using FTIR and XRD. XRD analysis shows that the crystallinity decreased within the composites due to breaking H-bonding. Compared to HPMC/shellac, TGA/DTG demonstrated the composite films' superior thermal stability. TiO2 (0.08-0.16 %) was cast into a composite film comprising HPMC, shellac, and GO. The homogeneity of TiO2 distribution in the composite film was shown using a SEM, which was also used to display the morphology of nanocomposite films. Nanocomposite films' thickness, air permeability, tensile strength, Young's modulus, and burst strength were examined. The results demonstrated that natural films prepared by a combination of shellac/GO with HPMC enhanced the fabricating of films' properties, the tensile strength increased by 231 % (from 16 to 53 MPa) in HPMC and HPSG2 (HPMC 1.9 g/shellac 0.25 g/GO 0.125 g in 100 mL) respectively, whereas the contact angle did not change. And after addition of TiO2-NPs, there were high enhancements in HPMC films' properties, such tensile strength increased by 212 % (from 16 to 50 MPa), burst strength increased by 20.96 % (3.1 to 3.75 Kg/cm2), and the contact angle by 60.86 % (48 to 74°) in HPMC and HPSGT2 respectively. Compared to HPMC films, films exhibited the highest levels of antibacterial activity against E. coli, B. mycoides, and C. albicans. So, the composite films from HPMC/shellac/GO/TiO2-NPs are promising potential packaging materials.