Recent Trends in Drug Delivery and Emerging Biomedical Applications of Gelatin for Ophthalmic Indications

Development and evaluation of ocular antibiotic-loaded soluble film inserts

Antibiotic eyedrops typically require frequent instillation due to the eye's defensive mechanisms limiting drugs from reaching target sites. This may risk patient non-adherence and treatment inefficacy. The aim of this study was to develop a biocompatible and fully soluble ocular film insert to enhance the delivery of levofloxacin, as well as the handling procedure for its administration; based on the anatomical dimensions and physiological conditions of the human eye. Inserts were prepared by solvent casting method, using HPMC, sodium alginate, gelatin, PEG 400, and levofloxacin solution, and characterised for various physicochemical properties (e.g., uniformity of weight and thickness, loss on dryness, swelling index, water uptake and surface pH). Mechanical properties were assessed and compared against a commercially available buccal film formulation. Uniformity of content and release profile of inserts were assessed by means of a validated analytical method. Antibacterial effectiveness was studied by adapted disc diffusion method on Staphylococcus aureus and Pseudomonas aeruginosa. The formulation including HPMC E15 (1250 mg), low viscosity sodium alginate (750 mg), type A gelatin (250 mg) and PEG 400 (2.5 mL) and 0.1% levofloxacin solution, resulted in high quality inserts, exhibiting uniformity of mass, thickness, and levofloxacin content, that comply with Pharmacopeial standards. Inserts were able to withstand unilinear and repeated mechanical stresses, suggesting suitability for manipulation linked to eye administration. The fully soluble levofloxacin-loaded inserts exhibited good physicochemical and mechanical characteristics, indicating good compatibility with ocular environment and administration procedure. Consistent levofloxacin content and biphasic release pattern showed immediate and sustained antimicrobial efficacy, consistently above the minimum inhibitory concentrations for the model species tested. This work also presents an experimental framework that can be adapted for designing and testing ocular drug delivery systems accounting for anatomical and physiological characteristics of the eye.

Zein: Potential biopolymer in inflammatory bowel diseases

Effectively managing inflammatory bowel disease (IBD) poses difficulties due to its persistent nature and unpredictable episodes of exacerbation. There is encouraging evidence that personalized medication delivery systems can improve therapy efficacy while reducing the negative effects of standard medicines. Zein, a protein produced from corn, has garnered interest as a possible means of delivering drugs for the treatment of IBD. This review delves into Zein-based drug delivery systems, showcasing its biodegradability, controlled release capabilities, and biocompatibility. Studies have shown that Zein-based nanoparticles, microcarriers, and core-shell microparticles have the capacity to increase medication stability, enhance targeting in the intestines, and decrease toxicity in animal models of IBD. The review highlights the promise of Zein in personalized therapy for IBD and urges more study to enhance its clinical use.

Achieving Endo/Lysosomal Escape Using Smart Nanosystems for Efficient Cellular Delivery

The delivery of therapeutic agents faces significant hurdles posed by the endo-lysosomal pathway, a bottleneck that hampers clinical effectiveness. This comprehensive review addresses the urgent need to enhance cellular delivery mechanisms to overcome these obstacles. It focuses on the potential of smart nanomaterials, delving into their unique characteristics and mechanisms in detail. Special attention is given to their ability to strategically evade endosomal entrapment, thereby enhancing therapeutic efficacy. The manuscript thoroughly examines assays crucial for understanding endosomal escape and cellular uptake dynamics. By analyzing various assessment methods, we offer nuanced insights into these investigative approaches' multifaceted aspects. We meticulously analyze the use of smart nanocarriers, exploring diverse mechanisms such as pore formation, proton sponge effects, membrane destabilization, photochemical disruption, and the strategic use of endosomal escape agents. Each mechanism's effectiveness and potential application in mitigating endosomal entrapment are scrutinized. This paper provides a critical overview of the current landscape, emphasizing the need for advanced delivery systems to navigate the complexities of cellular uptake. Importantly, it underscores the transformative role of smart nanomaterials in revolutionizing cellular delivery strategies, leading to a paradigm shift towards improved therapeutic outcomes.

Light-responsive polymeric nanoparticles for retinal drug delivery: design cues, challenges and future perspectives

A multitude of sight-threatening retinal diseases, affecting hundreds of millions around the globe, lack effective pharmacological treatments due to ocular barriers and common drug delivery limitations. Polymeric nanoparticles (PNPs) are versatile drug carriers with sustained drug release profiles and tunable physicochemical properties which have been explored for ocular drug delivery to both anterior and posterior ocular tissues. PNPs can incorporate a wide range of drugs and overcome the challenges of conventional retinal drug delivery. Moreover, PNPs can be engineered to respond to specific stimuli such as ultraviolet, visible, or near-infrared light, and allow precise spatiotemporal control of the drug release, enabling tailored treatment regimens and reducing the number of required administrations. The objective of this study is to emphasize the therapeutic potential of light-triggered drug-loaded polymeric nanoparticles to treat retinal diseases through an exploration of ocular pathologies, challenges in drug delivery, current production methodologies and recent applications. Despite challenges, light-responsive PNPs hold the promise of substantially enhancing the treatment landscape for ocular diseases, aiming for an improved quality of life for patients.

An insight on ophthalmic drug delivery systems: Focus on polymeric biomaterials-based carriers

Presently, different types of eye diseases, such as glaucoma, myopia, infection, and dry eyes are treated with topical eye drops. However, due to ocular surface barriers, eye drops require multiple administrations, which may cause several risks, thereby necessitating additional strategies. Some of the key characteristics of an ideal ocular drug delivery system are as follows: (a) good penetration into cornea, (b) high drug retention in the ocular tissues, (c) targetability to the desired regions of the eye, and (d) good bioavailability. It is worthy to note that the corneal epithelial tight junctions hinder the permeation of therapeutics through the cornea. Therefore, it is necessary to design nanocarriers that can overcome these barriers and enhance drug penetration into the inner parts of the eye. Moreover, intelligent multifunctional nanocarriers can be designed to include cavities, which may help encapsulate sufficient amount of the drug. In addition, nanocarriers can be modified with the targeting moieties. Different types of nanocarriers have been developed for ocular drug delivery applications, including emulsions, liposomes, micelles, and nanoparticles. However, these formulations may be rapidly cleared from the eye. The therapeutic use of the nanoparticles (NPs) is also hindered by the non-specific adsorption of proteins on NPs, which may limit their interaction with the cellular moieties or other targeted biological factors. Functional drug delivery systems (DDS), which can offer targeted ocular drug delivery while avoiding the non-specific protein adsorption could exhibit great potential. This could be further realized by the on-demand DDS, which can respond to the stimuli in a spatio-temporal fashion. The cell-mediated DDS offer another valuable platform for ophthalmological drug delivery.

Collagen-Based Hydrogels for the Eye: A Comprehensive Review

Collagen-based hydrogels have emerged as a highly promising platform for diverse applications in ophthalmology, spanning from drug delivery systems to biomedical interventions. This review explores the diverse sources of collagen, which give rise to different types of collagen protein. The critical isolation and purification steps are discussed, emphasizing their pivotal role in preparing collagen for biomedical use. To ensure collagen quality and purity, and the suitability of collagen for targeted applications, a comprehensive characterization and quality control are essential, encompassing assessments of its physical, chemical, and biological properties. Also, various cross-linking collagen methods have been examined for providing insight into this crucial process. This comprehensive review delves into every facet of collagen and explores the wide-ranging applications of collagen-based hydrogels, with a particular emphasis on their use in drug delivery systems and their potential in diverse biomedical interventions. By consolidating current knowledge and advancements in the field, this review aims to provide a detailed overview of the utilization of engineered collagen-based hydrogels in ocular therapeutics.

"Bioinspired" Membrane-Coated Nanosystems in Cancer Theranostics: A Comprehensive Review

Achieving precise cancer theranostics necessitates the rational design of smart nanosystems that ensure high biological safety and minimize non-specific interactions with normal tissues. In this regard, "bioinspired" membrane-coated nanosystems have emerged as a promising approach, providing a versatile platform for the development of next-generation smart nanosystems. This review article presents an in-depth investigation into the potential of these nanosystems for targeted cancer theranostics, encompassing key aspects such as cell membrane sources, isolation techniques, nanoparticle core selection, approaches for coating nanoparticle cores with the cell membrane, and characterization methods. Moreover, this review underscores strategies employed to enhance the multi-functionality of these nanosystems, including lipid insertion, membrane hybridization, metabolic engineering, and genetic modification. Additionally, the applications of these bioinspired nanosystems in cancer diagnosis and therapeutics are discussed, along with the recent advances in this field. Through a comprehensive exploration of membrane-coated nanosystems, this review provides valuable insights into their potential for precise cancer theranostics.