Matrix hyaluronic acid and bilayer poly-hydroxyethyl methacrylate-hyaluronic acid films as potential ocular drug delivery platforms

Medicated and multifunctional composite alginate-collagen-hyaluronate based scaffolds prepared using two different crosslinking approaches show potential for healing of chronic wounds

Chronic wounds present significant challenges with high morbidity and mortality. A cost-effective dressing that can absorb large exudate volumes, is hemostatic and therapeutically active is of current interest. This study compares two crosslinking approaches on composite scaffolds comprising fish collagen (FCOL), hyaluronic acid (HA) and sodium alginate (SA) by respectively targeting HA and SA. Crosslinking involved reacting HA with polyethylene glycol diglycidyl ether (PEGDE)/itaconic acid (IT) (IPC scaffolds) or SA with calcium chloride (CC scaffolds) and the crosslinked gels (with/without BSA) freeze-dried. Selected optimized formulations were loaded with basic fibroblast growth factor (b-FGF) as medicated scaffold dressings. NMR and FTIR spectroscopies (crosslinking/component interactions), SEM (morphology), texture analysis (mechanical strength/adhesion), and exudate handling were used to characterize the physico-chemical properties of the scaffolds. Protein (BSA) release profiles, hemostasis, biocompatibility and wound closure were assessed using HPLC, whole blood and methyl thiazolyl tetrazolium (MTT) and scratch assays respectively. The CC SA:FCOL:HA scaffolds showed improved mechanical strength, porosity, water vapor transmission rate, retained structural integrity after absorbing 50% exudate and promoted cell proliferation. The IPC scaffolds showed enhanced structural integrity, excellent hemostasis, retained three times more exudate than non-crosslinked scaffolds and provided acceptable pore size for cell adhesion and proliferation. The results show potential of CC and IPC SA:FCOL:HA scaffolds as medicated dressings for delivering proteins to chronic wounds. The study's significance lies in their potential use as multifunctional, multi-targeted and therapeutic dressings to overcome challenges with chronic wounds and use as delivery platforms for other therapeutic agents for chronic wound healing.

Citric acid crosslinked hydroxyethyl tamarind gum-based hydrogel films: A promising biomaterial for drug delivery

This investigation explored citric acid crosslinked hydroxyethyl tamarind gum hydrogel films as a potential biomaterial for drug delivery. Hydroxyethylation of tamarind gum aimed to improve its solubility, swelling, and crosslinking potential. The synthesized hydroxyethylated tamarind gum (HETG) was comprehensively characterized, revealing the presence of hydroxyethyl groups and increased viscosity in comparison to unmodified tamarind gum. The citric acid crosslinked HETG hydrogel films were developed by esterification-crosslinking mechanism. The films were characterized using instrumental techniques and evaluated for total carboxyl content, mechanical properties, swelling behavior, drug loading, drug release, antibacterial activity, hemocompatibility and in vitro wound healing activity. The presence of ester crosslinks and extent of crosslinking was confirmed through total carboxyl content and instrumental analysis. Varying HETG (2-2.5%w/v) and citric acid (1-1.4 %w/v) concentrations resulted in films with tunable mechanical strength, swelling, and drug loading. The films effectively controlled the release of a water-soluble drug (80.87-99.70 % in 24 h) through a non-Fickian diffusion mechanism. The optimized HETG hydrogel film showed antimicrobial activity, hemocompatibility, and support for cell growth, confirming its biocompatibility and potential for wound healing. Citric acid-crosslinked HETG films appear promising for drug delivery to wounds, meriting further in vivo study.

Adaptive covalently assembled thymopentin/hyaluronic acid based anti-inflammatory drug carrier with injectability and controlled release

Developing bioactive delivery carriers with anti-inflammatory functions, long-term administration, and controlled release of multiple drugs is highly desirable owing to disease persistence over an extended period. In this study, a dynamically induced covalent assembly approach was used to fabricate thymopentin (TP5)-based carrier particles (TGCP) with biocompatibility and autofluorescence. The size and dispersibility of TGCP can be modulated by non-covalent interactions with hyaluronic acid (HA), endowing the system with excellent injectability and synergistic anti-inflammatory activity. Interestingly, the carrier can load a wide range of guest molecules with varying solubilities and achieve controlled gradient release in pathological and physiological environments. In addition, traditional Chinese-medicine-loaded TGCP/HA can effectively reduce the level of the inflammatory factor IL-6, indicating its potential anti-inflammatory properties. The TP5/HA-based material possesses excellent carrier properties and immunoreactivity, making it attractive for reducing inflammation at disease sites and long-term drug delivery in various chronic diseases.

Nanomedicine in glaucoma treatment; Current challenges and future perspectives

Glaucoma presents a significant global health concern and affects millions of individuals worldwide and predicted a high increase in prevalence of about 111 million by 2040. The current standard treatment involves hypotensive eye drops; however, challenges such as patient adherence and limited drug bioavailability hinder the treatment effectiveness. Nanopharmaceuticals or nanomedicines offer promising solutions to overcome these obstacles. In this manuscript, we summarized the current limitations of conventional antiglaucoma treatment, role of nanomedicine in glaucoma treatment, rational design, factors effecting the performance of nanomedicine and different types of nanocarriers in designing of nanomedicine along with their applications in glaucoma treatment from recent literature. Current clinical challenges that hinder real-time application of antiglaucoma nanomedicine are highlighted. Lastly, future directions are identified for improving the therapeutic potential and translation of antiglaucoma nanomedicine into clinic.

Recent advances on chitosan/hyaluronic acid-based stimuli-responsive hydrogels and composites for cancer treatment: A comprehensive review

Cancer, as leading cause of death, has a high rate of mortality worldwide. Although there is a wide variety of conventional approaches for the treatment of cancer (such as surgery and chemotherapy), they have considerable drawbacks in terms of practicality, treatment efficiency, and cost-effectiveness. Therefore, there is a fundamental requirement for the development of safe and efficient treatment modalities based on breakthrough technologies to suppress cancer. Chitosan (CS) and hyaluronic acid (HA) polysaccharides, as FDA-approved biomaterials for some biomedical applications, are potential biopolymers for the efficient treatment of cancer. CS and HA have high biocompatibility, bioavailability, biodegradability, and immunomodulatory function which guarantee their safety and non-toxicity. CS-/HA-based hydrogels (HGs)/composites stand out for their potential anticancer function, versatile preparation and modification, ease of administration, controlled/sustained drug release, and active and passive drug internalization into target cells which is crucial for efficient treatment of cancer compared with conventional treatment approaches. These HGs/composites can respond to external (magnetic, ultrasound, light, and thermal) and internal (pH, enzyme, redox, and ROS) stimuli as well which further paves the way to their manipulation, targeted drug delivery, practicality, and efficient treatment. The above-mentioned properties of CS-/HA-based HGs/composites are unique and practical in cancer treatment which can ignore the deficiencies of conventional approaches. The present manuscript comprehensively highlights the advances in the practical application of stimuli-responsive HGs/composites based on CS/HA polysaccharides.

Carrageenan films as promising mucoadhesive ocular drug delivery systems

Polymer mucoadhesive films being developed for use in ophthalmology represent a new tool for drug delivery and are considered an alternative to traditional dosage forms. Due to their mucoadhesive properties, carrageenans (CRGs) are widely used in various forms for drug delivery. In this study, films based on CRGs of various structural types (κ/β, κ, x, and λ) for use in ophthalmology were studied. The films were loaded with the active substance echinochrome (ECH), a sea urchin pigment used in ophthalmology. Spectral data showed that ECH remained stable after its incorporation into the CRG films and did not oxidize for at least six months. Hydrophilic CRG films with a thickness of 10-12 µm were characterized in terms of their swelling and mucoadhesive properties. The rheological properties of solutions formed after film dissolution in artificial tears were also assessed. κ- and κ/β-CRG films with ECH exhibited pseudoplastic behavior after rehydrating films with an artificial tear solution. The CRG-loaded films had different swelling characteristics depending on the structure of the CRG used. The films based on highly sulfated CRGs dissolved in artificial tears, while the films of low-sulfated κ/β-CRG exhibited limited swelling. All studied ECH-loaded films exhibited mucoadhesive properties, which were evaluated by a texture analyzer using mucous tissue of the small intestine of the pig as a model. There was a slight prolongation of ECH release from CRG films in artificial tears. The effect of CRG/ECH on the epithelial cell lines of the outer shell of the human eye was investigated. At low concentrations, ECH in the composition of the CRG/ECH complex had no cytotoxic effect on corneal epithelial and conjunctival human cells. The use of ECH-containing films can prevent the drug from being immediately washed away by tears and help to retain it by increasing viscosity and having mucoadhesive properties.