Preparation and evaluation of blend polymer films for wound dressing using vancomycin-loaded polycaprolactone and carboxymethyl cellulose via crosslinking methods: Effect of mechanical strength, antibacterial activity, and cytotoxicity.

Polycaprolactone (PCL) and carboxymethyl cellulose (CMC) are two materials with beneficial properties for wound healing applications. Here, the simple preparation of PCL/CMC polymer films via the crosslinking method was demonstrated for the first time. The polymer films represented the suitable properties of liquid absorption and tensile strength to be used as a wound dressing. The blend polymer films can also load the vancomycin, which prolongs the drug release for effectiveness against S. aureus. The trifluoroethanol showed less toxicity in comparison with other crosslinking agents. This process can also be applied further in other medical devices and wound healing applications.

Development of Nanoemulsions for Wound Dressings Containing Cassia alata L. Leaf Extraction.

Natural polymer-based hydrogel films possess considerable potential for use in biomedical applications and are excellent for wound healing. The purpose of this research was to use ionic crosslinking to improve the mechanical characteristics, absorption of fluid in the wound, and drug release behavior of Cassia alata L. (CA) extract loaded niosomes (CANs) that were incorporated in an alginate-pectin film (A/P). Then, chemically crosslinked A/P hydrogels were obtained by immersing them in different concentrations of calcium chloride (CaCl2) (0.5-1% w/v) for 15-120 s. The degree of crosslinking was controlled by both contact time and CaCl2 concentration. The optimal crosslinking conditions were 1% CaCl2 for 15 seconds. In this study, the following features of the hydrogel films were investigated: physical properties, morphological characteristics, drug loading, in vitro drug release, antibacterial activity, wound healing activity, cytocompatibility profiles, and hemocompatibility. The crosslinked hydrogel films maintained their physical integrity during use, with the 1% film attaining the best results in the shortest period (15 sec). Then, in vitro drug release from the films was examined. Crosslinking was observed to prolong the release of the CA extract from the hydrogel film. Finally, a cell viability experiment was conducted to evaluate the cytotoxicity profile. The A/P composite film exhibited excellent wound dressing qualities and good mechanical properties in preformulation testing. The in vitro drug release profile indicated that the A/P created a regulated drug release profile, and the cell viability experiment revealed that the film was nontoxic and hemocompatible. A/P composite films can be produced using CAN extract as a possible wound dressing. However, further studies in animals and humans are required to determine both safety and effectiveness.

In silico investigation of ACE2 and the main protease of SARS-CoV-2 with phytochemicals from Myristica fragrans (Houtt.) for the discovery of a novel COVID-19 drug.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), is a new coronavirus strain that was first reported in December 2019 in Wuhan, China. A specific treatment for COVID-19 has yet to be identified. Potential therapeutic targets include SARS-CoV-2 main protease (Mpro) and the SARS-CoV-2 spike-ACE2 interaction. Molecular docking, molecular dynamics (MD), solvent screening for the extraction of the specified compounds, and prediction of the drug properties of certain molecules were the methods used in this study to investigate compounds from the medicinal plant Myristica fragrans, which is one of twelve herbs in Prasachandaeng remedy (PSD). ArgusLab, AutoDock Vina, and AutoDock were used to perform docking tasks. The examined ligands were compared with panduratin A as a standard (Kanjanasirirat et al., 2020), which is a promising medicinal plant molecule for the treatment of COVID-19. Molecular docking revealed that malabaricones B and C and licarins A, B and C bound to SARS-CoV-2/ACE2 and SARS-CoV-2 Mpro with low binding energies compared to that of the standard ligand. Furthermore, appropriate solvent usage is important. Acetone was selected by COSMOquick software for compound extraction in this investigation because it can extract large amounts of all five of the abovementioned M. fragrans compounds. Furthermore, the drug-like properties of these compounds were studied utilizing the Lipinski, Veber, and Ghose criteria. The results revealed that these M. fragrans compounds have potential as effective medicines to combat the COVID-19 pandemic. However, to assess the therapeutic potential of these ligands, additional research is needed, which will use our findings as a foundation.

In vivo catheterization study of chlorhexidine-loaded nanoparticle coated Foley urinary catheters in male New Zealand white rabbits.

Foley urinary catheters were coated with chlorhexidine-loaded nanoparticles (CHX-NPs), encapsulated in the form of micelles and nanospheres. Both of nanoparticles were deposited by multilayer nanocoating through dip and spray coating on the catheter surface both inner and outer surface. In our previous studies, the nanocoating of Foley urinary catheters was studied for chlorhexidine release, degradation, antibacterial evaluation, cytotoxicity assessment, hemocompatibility, skin irritation, skin sensitization, and stability during storage. The results demonstrated the antimicrobial functions and biocompatibility of the coated catheters. In this study, coated urinary catheters were inserted in the bladders of rabbits for 7 day to investigate their efficacy. Histopathology results showed no inflammation, redness, or swelling on bladder and urethra tissues. Surface morphology comparison of uncoated catheters in the control group and coated catheters in the treatment group revealed more encrustation and crystallization on uncoated catheter than on coated catheter, indicating that catheters coated with CHX-NPs showed efficacy in delaying encrustation and bacterial colonization. These findings suggest that nanocoating of urinary catheters can potentially enhance the biocompatibility of medical devices.

Biocompatibility and stability during storage of Foley urinary catheters coated chlorhexidine loaded nanoparticles by nanocoating: in vitro and in vivo evaluation.

Foley urinary catheters were coated by chlorhexidine-loaded micelles and chlorhexidine-loaded nanospheres. In our prior study, the nanocoating of Foley urinary catheter was investigated for chlorhexidine-release study, degradation, antibacterial evaluation, and cytotoxicity assessment. These studies presented the 1 month antibacterial property of nanocoating deposited via the layers of micelles and nanospheres. In this study, we evaluated the biocompatibility of these catheters, including hemocompatibility, skin irritation, skin sensitization, and stability during the age of coated urinary catheter. Results demonstrated that coated urinary catheters presented slight hemolysis, whereas skin irritation on rabbit and skin sensitization on Dunkin Hartley guinea pig showed no signs of dermal toxicity, which indicated that inflammation, redness, and swelling did not occur. Moreover, the stability of coated urinary catheters during storage indicated no change in chlorhexidine peaks by high performance liquid chromatography. Information from these studies supports the biocompatibility of coated urinary catheters via nanocoating and their use as indwelling devices to prevent urinary tract infections.

Spray coating of foley urinary catheter by chlorhexidine-loadedpoly(ε-caprolactone) nanospheres: effect of lyoprotectants, characteristics, and antibacterial activity evaluation.

In this study, chlorhexidine-loaded poly(ε-caprolactone) nanospheres (CHX-NS) were prepared and successfully coated on the urinary catheters. Properties of CHX-NS were evaluated including drug loading content and the nanosphere size. Effects of different lyoprotectants for long-term storage of CHX-NS were also investigated. In vitro release study and antibacterial activity were also conducted using 20 cycles coated-urinary catheters. Results showed that the high-pressure emulsification-solvent evaporation technique provided the drug loading content at 1.14 ± 0.16% and the size of nanospheres was 152 ± 37 nm. The suitable lyoprotectant for long-term storage of CHX-NS was sucrose which provided noticeably no aggregation at the degree of reconstitution at 89.95%. The amount of CHX loading on coated catheters was at 4.55 ± 0.31 mg. Drug release from the coated catheters in artificial urine could be prolonged up to 2 weeks and bacteria proliferation was inhibited up to 14 days. These results suggest that the antimicrobial activity of CHX-NS reduces the adherence of the uropathogens to the catheter surface. Chlorhexidine-loaded polymeric nanospheres were fabricated which can be successfully coated on urinary catheters. These systems have potential use for prolonged antimicrobial applications.

Development of antimicrobial coating by layer-by-layer [corrected] dip coating of chlorhexidine-loaded micelles.

Layer-by-layer (LbL) dip coating, accompanying with the use of micelle structure, allows hydrophobic molecules to be coated on medical devices' surface via hydrogen bonding interaction. In addition, micelle structure also allows control release of encapsulated compound. In this research, we investigated methods to coat and maximize the amount of chlorhexidine (CHX) on silicone surface through LbL dip coating method utilizing hydrogen bonding interaction between PEG on micelle corona and PAA. The number of coated cycles was varied in the process and 90 coating cycles provided the maximum amount of CHX loaded onto the surface. In addition, pre-coating the surface with PAA enhanced the amount of coated CHX by 20%. Scanning electron microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to validate and characterize the coating. For control release aspect, the coated film tended to disrupt at physiological condition; hence chemical crosslinking was performed to minimize the disruption and maximize the release time. Chemical crosslinking at pH 2.5 and 4.5 were performed in the process. It was found that chemical crosslinking could help extend the release period up to 18 days. This was significantly longer when compared to the non-crosslinking silicone tube that could only prolong the release for 5 days. In addition, chemical crosslinking at pH 2.5 gave higher and better initial burst release, release period and antimicrobial properties than that of pH 4.5 or the normal used pH for chemical crosslinking process.