Nanoparticle-laden contact lens for controlled release of vancomycin with enhanced antibiotic efficacy

Structural Color Contact Lenses from Cholesteric Cellulose Liquid Crystals

Colored contact lenses have gained popularity among young individuals owing to their ability to alter the appearance of the wearer's eyes. However, conventional lenses containing chemical dyes are susceptible to detachment of the pigment layer, which can lead to corneal damage. In this research, a novel cellulose-based structural color contact lens (SCCL) is presented that enhances aesthetic appeal via a cholesteric liquid crystal (CLC) layer. Methacrylate-functionalized hydroxypropyl cellulose (HPCMA) molecules self-assemble into CLC and are cross-linked within the lens mold, resulting in the colored iris region of the contact lens. By employing multistep polymerization techniques, lenses with composite colors and intricate shapes are fabricated. Moreover, by incorporating bioderived antimicrobial peptides into the structurally colored region of the lens, SCCLs are achieved with good biocompatibility, controlled drug release, and broad-spectrum antibacterial activity. The results of in vivo experiments using an animal model indicate that the SCCLs perform well in the treatment of bacterial keratitis. It is believed that these drug-loaded structurally colored contact lenses will lead to various advancements in ocular medical devices and provide antibacterial protection against infectious keratitis in the future.

Development of Stimuli-Responsive Polymeric Nanomedicines in Hypoxic Tumors and Their Therapeutic Promise in Oral Cancer

Hypoxic tumors pose considerable obstacles to cancer treatment, as diminished oxygen levels can impair drug effectiveness and heighten therapeutic resistance. Oral cancer, a prevalent malignancy, encounters specific challenges owing to its intricate anatomical structure and the technical difficulties in achieving complete resection, thereby often restricting treatment efficacy. The impact of hypoxia is particularly critical in influencing both the treatment response and prognosis of oral cancers. This article summarizes and examines the potential of polymer nanomedicines to address these challenges. By engineering nanomedicines that specifically react to the hypoxic tumor microenvironment, these pharmaceuticals can markedly enhance targeting precision and therapeutic effectiveness. Polymer nanomedicines enhance therapeutic efficacy while reducing side effects by hypoxia-targeted accumulation. The article emphasizes that these nanomedicines can overcome the drug resistance frequently observed in hypoxic tumors by improving the delivery and bioavailability of anticancer agents. Furthermore, this review elucidates the design and application of polymer nanomedicines for treating hypoxic tumors, highlighting their transformative potential in cancer therapy. Finally, this article gives an outlook on stimuli-responsive polymeric nanomedicines in the treatment of oral cancer.

Contact Lenses in Therapeutic Care: A Comprehensive Review of Past Innovations, Present Applications, and Future Directions

Contact lenses have become integral tools in the realm of ocular therapeutics, extending beyond their primary function of refractive correction to encompass a diverse array of therapeutic applications. This review explores the evolving role of contact lenses in managing various ocular conditions, highlighting their efficacy in enhancing patient outcomes. Initially developed to correct refractive errors, contact lenses now serve as effective vehicles for delivering medications directly to the ocular surface, offering targeted treatment for conditions such as dry eye syndrome and corneal ulcers. Their ability to provide sustained moisture and facilitate drug absorption makes them indispensable in promoting corneal healing and managing chronic ocular surface diseases. Specialized contact lenses designed for irregular corneas, such as those affected by keratoconus, provide both optical correction and structural support, significantly improving visual acuity and patient comfort. Additionally, orthokeratology lenses have shown promise in controlling myopia progression in children by reshaping the cornea overnight, thereby reducing reliance on corrective eyewear during waking hours. In post-surgical settings, therapeutic contact lenses aid in epithelial regeneration and minimize discomfort, accelerating recovery and improving surgical outcomes. They also play a crucial role in protecting the cornea from external irritants and promoting a stable tear film, crucial for maintaining ocular health. Looking ahead, ongoing advancements in contact lens materials and designs promise further innovation in ocular therapeutics, paving the way for personalized treatment strategies and improved patient care. As such, contact lenses continue to evolve as essential therapeutic tools, offering tailored solutions for a spectrum of ocular conditions and contributing to enhanced quality of life for patients worldwide.

Rational design of antibiotic-free antimicrobial contact lenses: Trade-offs between antimicrobial performance and biocompatibility

Microbial keratitis associated with contact lenses (CLs) wear remains a significant clinical concern. Antibiotic therapy is the current standard of care. However, the emergence of multidrug-resistant pathogens necessitates the investigation of alternative strategies. Antibiotic-free antimicrobial contact lenses (AFAMCLs) represent a promising approach in this regard. The effectiveness of CLs constructed with a variety of antibiotic-free antimicrobial strategies against microorganisms has been demonstrated. However, the impact of these antimicrobial strategies on CLs biocompatibility remains unclear. In the design and development of AFAMCLs, striking a balance between robust antimicrobial performance and optimal biocompatibility, including safety and wearing comfort, is a key issue. This review provides a comprehensive overview of recent advancements in AFAMCLs technology. The focus is on the antimicrobial efficacy and safety of various strategies employed in AFAMCLs construction. Furthermore, this review investigates the potential impact of these strategies on CLs parameters related to wearer comfort. This review aims to contribute to the continuous improvement of AFAMCLs and provide a reference for the trade-off between resistance to microorganisms and wearing comfort. In addition, it is hoped that this review can also provide a reference for the antimicrobial design of other medical devices.

Palladium nanocrystals regulates scleral extracellular matrix remodeling in myopic progression by modulating the hypoxia signaling pathway Nrf-2/Ho-1

Myopia represents a widespread global public health concern influenced by a combination of environmental and genetic factors. The prevailing theory explaining myopia development revolves around scleral extracellular matrix (ECM) remodeling, characterized by diminished Type I collagen (Col-1) synthesis and increased degradation, resulting in scleral thinning and eye axis elongation. Existing studies underscore the pivotal role of scleral hypoxia in myopic scleral remodeling. This study investigates the peroxidase-like activity and catalytic performance of octahedral Palladium (Pd) nanocrystals, recognized as nanozymes with antioxidative properties. We explore their potential in reducing oxidative stress and alleviating hypoxia in human scleral fibroblasts (HSF) and examine the associated molecular mechanisms. Our results demonstrate the significant peroxidase-like activity of Pd nanocrystals. Furthermore, we observe a substantial reduction in oxidative stress in HSF under hypoxia, mitigating cellular damage. These effects are linked to alterations in Nrf-2/Ho-1 expression, a pathway associated with hypoxic stress. Importantly, our findings indicate that Pd nanocrystals contribute to attenuated scleral matrix remodeling in myopic guinea pigs, effectively slowing myopia progression. This supports the hypothesis that Pd nanocrystals regulate myopia development by controlling oxidative stress associated with hypoxia. Based on these results, we propose that Pd nanocrystals represent a novel and potential treatment avenue for myopia through the modulation of scleral matrix remodeling. This study introduces innovative ideas and directions for the treatment and prevention of myopia.

Recent advances in nanostructured delivery systems for vancomycin

Despite the development of new generations of antibiotics, vancomycin remained as a high-efficacy antibiotic for treating the infections caused by MRSA. Researchers have explored various nanoformulations, aiming to enhance the therapeutic efficacy of vancomycin. Such novel formulations improve the effectiveness of drug cargoes in treating bacterial infections and minimizing the risk of adverse effects. The vast of researches have focuses on enhancing the permeation ability of vancomycin through different biological barriers especially those of gastrointestinal tract. Increasing the drug loading and tuning the drug release from nanocarrier are other important goal for many conducted studies. This study reviews the newest nano-based formulations for vancomycin as a key antibiotic in treating hospitalized bacterial infections.

Nanoparticles of Thiolated Xanthan Gum for the Oral Delivery of Miconazole Nitrate: In Vitro and In Vivo Evaluation

The objective of this research was to develop a mucoadhesive delivery system that improves permeation for the administration of poorly absorbed oral medications. Thiolation of xanthan gum (XGM) was carried out by esterification with mercaptobutyric acid. Fourier-transformed infrared spectroscopy was used to confirm thiol-derivatization. Using Ellman's technique, it was revealed that the xanthan-mercaptobutyric acid conjugate had 4.7 mM of thiol groups in 2 mg/mL of polymeric solution. Using mucosa of sheep intestine, the mucoadhesive properties of XGM and thiolated xanthan gum (TXGM) nanoparticles were investigated and we found that TXGM had a longer bioadhesion time than XGM. The disulfide link that forms between mucus and thiolated XGM explains why it has better mucoadhesive properties than XGM. A study on in vitro miconazole (MCZ) release using phosphate buffer (pH 6.8) found that TXGM nanoparticles released MCZ more steadily than MCZ dispersion did. A 1-fold increase in the permeation of MCZ was observed from nanoparticles using albino rat intestine compared to MCZ. Albino rats were used to test the pharmacokinetics of MCZ, and the results showed a 4.5-fold increase in bioavailability. In conclusion, the thiolation of XGM enhances its bioavailability, controlled release of MCZ for a long period of time, and mucoadhesive activity.