Investigation of Chlorhexidine and Chitosan Gel-Based Coatings for the Prevention of Intravascular Catheter-Associated Infections Following Quality by Design Approach

Intravascular catheter-associated infections pose a significant threat to the health of patients because of biofilm formation. Hence, it is imperative to exploit cost-effective approaches to improve patient compliance. With this aim, our present study reported the potential of an antimicrobial polymeric gel coating of chitosan (CS) and chlorhexidine (CHX) on the marketed urinary catheters to minimize the risk of biofilm formation. The study involved the implementation of the Quality by Design (QbD) approach by identifying the critical parameters that can affect the coating of the catheter's surface in any possible way. Later, design of experiments (DoE) analysis affirmed the lack of linearity in the model for the studied responses in a holistic manner. Moreover, in vitro studies were conducted for the evaluation of various parameters followed by the antibiofilm study. The coating exhibited promising release of CHX in the artificial urinary media together with retention of the coating on the catheter's surface. Therefore, this study aims to emphasize the importance of a systematic and quality-focused approach by contributing to the development of a safe, effective, and reliable catheter coating to enhance intravascular catheter safety.

Antimicrobial and Antibiofilm Potential of Green-Synthesized Graphene-Silver Nanocomposite against Multidrug-Resistant Nosocomial Pathogens

Hospital-acquired infections (HAIs) pose a significant risk to global health, impacting millions of individuals globally. These infections have increased rates of morbidity and mortality due to the prevalence of widespread antimicrobial resistance (AMR). Graphene-based nanoparticles (GBNs) are known to possess extensive antimicrobial properties by inflicting damage to the cell membrane, suppressing virulence, and inhibiting microbial biofilms. Developing alternative therapies for HAIs and addressing AMR can be made easier and more affordable by combining nanoparticles with medicinal plants harboring antimicrobial properties. Hence, this study was undertaken to develop a novel graphene-silver nanocomposite via green synthesis using Trillium govanianum plant extract as a reducing agent. The resulting nanocomposite comprised silver nanoparticles embedded in graphene sheets. The antibacterial and antifungal properties of graphene-silver nanocomposites were investigated against several nosocomial pathogens, namely, Candida auris, Candida glabrata, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The nanocomposite displayed broad-range antimicrobial potential against the test pathogens, with minimum inhibitory concentrations (MICs) ranging between 31.25 and 125.0 µg/mL, and biofilm inhibition up to 80-96%. Moreover, nanocomposite-functionalized urinary catheters demonstrated hemocompatibility towards sheep erythrocytes and imparted anti-fouling activity to the biomaterial, while also displaying biocompatibility towards HEK 293 cells. Collectively, this investigation highlights the possible application of green-synthesized GBNs as an effective alternative to conventional antibiotics for combating multidrug-resistant pathogens.

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.

Nanotechnology Involved in Treating Urinary Tract Infections: An Overview

Considered as the most frequent contaminations that do not require hospitalization, urinary tract infections (UTIs) are largely known to cause significant personal burdens on patients. Although UTIs overall are highly preventable health issues, the recourse to antibiotics as drug treatments for these infections is a worryingly spread approach that should be addressed and gradually overcome in a contemporary, modernized healthcare system. With a virtually alarming global rise of antibiotic resistance overall, nanotechnologies may prove to be the much-needed 'lifebuoy' that will eventually suppress this prejudicial phenomenon. This review aims to present the most promising, currently known nano-solutions, with glimpses on clinical and epidemiological aspects of the UTIs, prospective diagnostic instruments, and non-antibiotic treatments, all of these engulfed in a comprehensive overview.

Antibacterial and biocompatibility studies of triple antibiotics-impregnated external ventricular drainage: In vitro and in vivo evaluation

Hydrocephalus is a neurological disease caused by an unusually high level of cerebrospinal fluid (CSF), which can be relieved by external ventricular drainage (EVD) insertion. However, the infection can lead to complications during the use of EVD. In this study, EVD was impregnated with three synergistic antibiotics, including rifampicin, clindamycin, and trimethoprim, to improve the antibacterial property. The impregnated drainage was studied for its characteristics in vitro and in vivo. Drug loading determination revealed that rifampicin had the highest concentration in the tube, followed by clindamycin and trimethoprim, respectively. In vitro cytotoxicity and hemolytic studies showed no toxic effects from antibiotics-impregnated EVD on fibroblast and red blood cells. For antibacterial testing, the impregnated EVD exhibited antibacterial activity against Staphylococcus aureus MRSA and Staphylococcus epidermidis up to 14 and 90 days, respectively. Moreover, biocompatibility and drug release into the bloodstream and surrounding tissues were investigated by implantation in rabbits for 30 days. Histology and morphology results showed that fibroblast cells began to adhere to the drainage surface and inflammatory cell numbers were noticeably small after the long-term implantation. In addition, there was no drug leakage to the bloodstream and surrounding tissues. Hence, this impregnated EVD can potentially be used for antibacterial application.

Alginate/pectin dressing with niosomal mangosteen extract for enhanced wound healing: evaluating skin irritation by structure-activity relationship

Most modern wound dressings assist the wound-healing process. In contrast, conventional wound dressings have limited antibacterial activity and promote sporadic fibroblast growth. Therefore, wound dressings with prolonged substance release must be improved. This research aimed to develop hydrogel films. These were synthesized from alginate and pectin, incorporated with mangosteen extract (ME), and encapsulated in niosomes (ME-loaded niosomes). Subsequently, we examined the in vitro release and physical characteristics of ME-loaded niosomes. These characteristics included particle pH, size, charge, polydispersity index (PDI), and drug loading properties. These properties included drug loading content (DLC), entrapment efficiency (EE), and yield (Y). Additionally, we examined the swelling ratio and biological characteristics of the hydrogel film. These characteristics included antibacterial activity, cytotoxicity (L929), cell attachment to the tested materials, cell migration, hemocompatibility, and in vivo irritation. Significant results were obtained using a 2:1 niosome preparation containing Span60 and cholesterol. Ratio influenced size, charge, PDI, DLC, EE, and Y. The results were 225.5 ± 5.83 nm, negatively charged, 0.38, 16.2 ± 0.87%, 64.8 ± 3.49%, and 87.3 ± 3.09%, respectively. Additionally, the release of encapsulated ME was pH sensitive because 85% of the ME can be released at a pH of 5.5 within seven days and decrease to 70% at a pH of 7.4. The maximum swelling ratios of patches with 0.5% and 1% Ca2+ crosslinking were 867 wt% and 1,025 wt%, respectively, after 30 min. These results suggested that a medium dose (15 mg) of niosomal ME incorporated in a hydrogel film provided better bacterial inhibition, cell migration, and cell adhesion in an in vitro model. Additionally, no toxicity was observed in the fibroblasts and red blood cells. Therefore, given the above-mentioned advantages, this product can be a promising candidate for wound dressing applications.

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.

Novel rhein integrate transphytosomes as non-invasive local therapy for osteoarthritis to ameliorate cartilage deterioration in MIA-arthritic rats

Rhein (RH), a natural chondroprotective agent, suffers from poor systemic availability (20-25%) after oral administration concomitant to side effects on the gastrointestinal tract and liver. We present a new approach for non-invasive local targeted delivery of rhein to ameliorate cartilage deterioration employing cartilage-homing phospholipids nanocarriers. This is the first work to elaborate RH loaded transphytosome (RH-T-PHY) as novel nanovesicular systems for transdermal drug delivery based on an advantageous hybrid between phytosomes and transfersomes or bilosomes. Here, we developed transphytosomes through incorporating various edge activators (EAs) such as Tween 80, Span 80 and sodium deoxycholate into the lipid bilayer of RH phytosomes to affix the flexibility. RH-T-PHY with high flexibility and entrapment efficacy showed the highest significant skin permeation compared to conventional phytosomes. Additionally, RH-T-PHY have a magnificent potential in maintaining high chondroprotective activity as demonstrated by enhanced repair, regeneration of chondrocytes and GAG formation in MIA-induced osteoarthritis (OA) rat model. Besides, histological examination of vital organs revealed the formulation safety. Confocal laser microscopy images revealed the highest drug availability in the articular cartilage of RH-T-PHY treated group. Conclusively, novel RH-T-PHY can serve as a promising alternative means for delivery of chondroprotective drugs for effective non-invasive local therapy of OA.