Drug Delivery Letters - Volume 15, Issue 4, 2025

Wound healing is an intricate biological process that is supported by well-coordinated cellular activities along with the influence of various factors, such as infection at the site of the wound, comorbidities, and lifestyle habits. Non-healing wounds pose a significant global health concern, with a substantial impact on healthcare resources and patient well-being. Wound dressings play a crucial role in creating an optimal microenvironment for healing, and the selection of an appropriate dressing is imperative to ensure faster healing and improved patient outcomes. Polyurethane (PU) foam based wound dressings have gained considerable attention owing to their versatile properties and potential applications in wound care. PU foam dressings are known for their high absorbency in managing moderate to heavy exudate, ability to maintain a moist wound environment, comfort, flexibility, and non-adherent properties. PU is the preferred substrate material for dressings because of its customizable mechanical properties, excellent biocompatibility, and low toxicity. Several studies have explored the use of polyurethane foam-based wound dressings and have highlighted their potential benefits and limitations. Despite the promising results of previous studies, there is still a lack of comprehensive understanding of the applications and challenges of PU foam-based wound dressings in wound healing. This review aims to address the knowledge gap by providing an update on the current state of research on polyurethane foam-based wound dressings and their potential applications and challenges in wound healing.

Cancer remains one of the most significant global health challenges, necessitating innovative therapeutic approaches to improve treatment efficacy and minimize side effects. Traditional methods such as chemotherapy, radiotherapy, and surgery, while effective to some extent, face limitations, including drug resistance, tumor recurrence, and systemic toxicity. In this context, microbial-based nanoparticles have emerged as a novel and promising solution in cancer therapy. These nanoparticles leverage the inherent properties of microbes, such as targeting and biocompatibility, in combination with nanotechnology to deliver drugs with precision, enhance bioavailability, and reduce off-target effects.

This review highlights recent advancements in microbial-derived nanoparticles, focusing on their mechanisms of action, such as immune modulation, tumor penetration, and drug delivery capabilities. Furthermore, it discusses their potential to overcome current therapeutic challenges, emphasizing safety, efficacy, and scalability. Microbial-based nanoparticles offer a pathway toward more patient-centered and precision-based therapeutic solutions by addressing critical gaps in existing cancer treatments. The review also explores the challenges of clinical translation, such as toxicity concerns, regulatory hurdles, and manufacturing complexities, while providing insights into future research directions to accelerate their application in clinical practice.

In recent times, Ethosome has become a new promising pharmaceutical nano-carrier for the development of innovative dermal and transdermal therapies that help in the treatment of various skin diseases like skin allergies, urticaria, melisma, eczema, melanoma, and other skin disease. Ethosome is a non-invasive, modified phospholipid-based elastic, soft vesicular nano-carrier with high ethanol content. Ethanol in this formulation facilitates rapid penetration of the drug into the skin accelerating cell membrane lipid fluidity. After permeation into the skin, those get fused with the cell membrane lipids and release the loaded drug. BCS III & IV drugs, having low permeability, can be developed with ethosomal systems. Histamine is one of the responsible biogenic factors for itching, skin wheals, allergies, other skin disorders, etc., so incorporation of low permeable antihistaminic drugs in ethosome is an emerging prospect in the field of dermatology and cosmetology. Ethosomes reflect positive insights to overcome side effects associated with conventional oral therapy, quick onset of action, and targeted drug delivery to inflamed skin. The concept of ethosome is considered advantageous over liposome to be more penetrable to the skin. Besides the need for further pharmacokinetic and pharmacodynamics studies on ethosome, it seems to significantly hold a great contemplation for the delivery of medicaments in the skin through different pathways.

The pH-sensitive drug delivery systems (PSDDS) are attracting significant attention as these systems transport the drug at a specific time as per the pathophysiological need of the disease, leading to improved patient therapeutic effectiveness and compliance. The pH-sensitive nanoparticles are a favorable alternative to treat ulcers, especially gastrointestinal ulcers comprising peptic ulcers and mouth ulcers. These nanoparticles can be intended to release medication in a meticulous way at specific pH levels of the ulcer site, which can improve therapeutic effectiveness and decrease side effects. It is significant to note that the use of pH-sensitive nanoparticles for ulcer management is an evolving field of research, and the specific applications and formulations may vary based on the type and location of the ulcer. Additionally, regulatory approvals and clinical trials may be necessary before such treatments become widely available to patients.

Research in ocular delivery of medication has both challenging and promising opportunities for the pharmaceutical sector. Present ocular delivery methods of drugs, including ointments, solutions, and suspensions, have a number of limitations, such as rapid elimination from the precorneal area, high variation in efficacy, and the risk of blurred vision. These disadvantages underscore the need for the introduction of more effective drug delivery systems. Research on ocular drug delivery has increased significantly in the past years, resulting in the use of numerous standard formulation forms, such as ointments and eye drops. One big drawback of the two formulations is the fast expulsion of the deposited dose through the action of blinking eyelids as well as the excretion of tear fluid. To counter this, in situ, gelling systems have been created that minimize drainage and prolong the period of contact with the ocular tissues and cornea. The formulations in these systems go through a sol-to-gel change due to conditions in the environment, for example, temperature, ionic strength, and pH. The transitions are usually triggered by the common polymers sodium alginate and high-performance methylcellulose. These preparations can be tested for any one of a number of properties, such as but not limited to clarity, ocular irritancy, texture, isotonicity, sterility, gel strength, gelling capacity, gelling time, ex-vivo release, in vitro drug release, stability, in vivo retention, and absorption.

Silk Sericin, a natural biopolymer, has gained increasing attention for its diverse applications in pharmaceuticals and biomedicine. This is an organic biomaterial derived from the Silkworm cocoon (silkworm Bombyx mori), by the degumming process, which exhibits remarkable biocompatibility, biodegradability, making it a promising candidate for various therapeutic and regenerative approaches. Sericinhas an excellent property that makes it a potential candidate for wound healing, skin care, and drug delivery applications. This hydrophilic protein is recognized as an anti-inflammatory, antioxidant, and anti-cancer agent. The high molecular weight and granular protein composition of sericin give it a sticky consistency and gelatin-like quality. The presence of many hydroxyl groups absorbs significant water from the skin, providing a natural moisturizing effect. Silk sericin presents a sustainable alternative to synthetic polymers, boasting exceptional characteristics, including minimal immune response, excellent moisture retention, and versatility in forming various structures such as films, fibers, and hydrogels. The sustained release of sericin from wound dressings can also be efficacious in providing a prolonged healing effect during the treatment of pressure ulcers. This can contribute to a more favourable environment for faster and effective wound healing. This review aims to provide a comprehensive overview of silksericin, highlighting its unique characteristics, extraction methods, and recent advancements in its utilization for pharmaceutical and biomedical purposes, along with emphasizing the significant potential of this protein as a versatile biopolymer for advanced healthcare solutions.

Recent years have witnessed an enormous spike in interest in cell-derived particles (CDPs) that are also called Extracellular vesicles (EVs) due to their potential uses in both treatments and diagnostics. Small vesicles or particles, including apoptotic bodies, microvesicles, and exosomes, are released from both healthy and sick cells. They carry bioactive substances from their parent cells and transfer this cargo to target cells making them potential candidates for therapeutic interventions and diagnostic applications. These phospholipid-enclosed nanovesicles have multiple benefits over other carriers of biological materials, including high biocompatibility, high circulation stability, core propensity to target cells, low immunogenicity, ability to shield payload from degradation and biological barrier-crossing properties that make them unique. Cell-derived particles are used for evaluating treatment efficacy in addition to treating diseases by tracking changes in the payload composition of extracellular vesicles over time as real-time monitoring, thus treatment plans can be improved and patient outcomes can be forecast. Moreover, extracellular vesicles have gained attention as possible biomarkers because of their capacity to hold and transport biomolecules, and many biomarkers which might provide important details about cellular functions and the onset of illness. Cell-derived particles reflect the condition of the parent cell, making them an excellent source of biomarkers for a variety of illnesses. They can reveal information about the existence and course of illnesses and serve as a noninvasive substitute for conventional tissue biopsies. This review highlights the potential of Extracellular vesicles (EVs) as drug delivery carriers and as novel non-invasive molecular diagnostic tools for the prognosis of fatal illnesses. This article reveals the fundamental characteristics of EVs, the types of EVs, characteristics of EVs as biomarkers. Further, challenges in the isolation and characterization of extracellular vesicles, and applications of extracellular vesicles in drug delivery, are also succinctly summarized in this review article.