Robust strategies to reduce burst and achieve tunable control over extended drug release from uniaxially electrospun composites

A systematic review of liposomal nanofibrous scaffolds as a drug delivery system: a decade of progress in controlled release and therapeutic efficacy

Drug-loaded liposomes incorporated in nanofibrous scaffolds is a promising approach as a multi-unit nanoscale system, which combines the merits of both liposomes and nanofibers (NFs), eliminating the drawback of liposomes' poor stability on the one hand and offering a higher potential of controlled drug release and enhanced therapeutic efficacy on the other hand. The current systematic review, which underwent a rigorous search process in PubMed, Web of Science, Scopus, Embase, and Central (Cochrane) employing (Liposome AND nanofib* AND electrosp*) as search keywords, aims to present the recent studies on using this synergic system for different therapeutic applications. The search was restricted to original, peer-reviewed studies published in English between 2014 and 2024. Of the 309 identified records, only 29 studies met the inclusion criteria. According to the literature, three different methods were identified to fabricate those nanofibrous liposomal scaffolds. The results consistently demonstrated the superiority of this dual system for numerous therapeutic applications in improving the therapy efficacy, enhancing both liposomes and drug stability, and releasing the encapsulated drug in a proper sustained release without significant initial burst release. Merging drug-loaded liposomes with NFs as liposomal nanofibrous scaffolds are a safe and efficient approach to deliver drug molecules and other substances for various pharmaceutical applications, particularly for wound dressing, tissue engineering, cancer therapy, and drug administration via the buccal and sublingual routes. However, further research is warranted to explore the potential of this system in other therapeutic applications.

Delivery of a novel neuroprotective compound to the retina in rat and rabbit animal models

Posterior segment-related diseases are among the leading causes of irreversible blindness and loss of vision globally. These diseases are extremely difficult to treat due to the drug delivery barriers posed by the eye, among other challenges. One delivery method that bypasses many of these obstacles, albeit not without risk, is ocular injections, and long-acting formulations such as implants can improve patient compliance by allowing for longer intervals between injections. Here, we report our development of a preclinical in situ-forming implant dosage form that provides sustained release of a novel compound, DKR-1677, with a target in the retina. An in situ-forming implant based on polylactic co glycolic acid (PLGA) was chosen in this preclinical stage because it is readily translatable to a preformed implant product. The formulations were tested in vitro, in rat and rabbit animal models for drug release and pharmacokinetics. A two-step in vitro dissolution method with implant formation in a biorelevant gel followed by incubation in release media showed a 30-day three-phase release profile with an initial burst release of 36.04 ± 4.23 %, a plateau, and a controlled release up to 93.75 ± 4.68 % at day 30, typical of PLGA-based implant formulations. Immediate and controlled-release formulations were tested in rat and rabbit animal models and confirmed that DKR-1677 is taken up by the retina after intravitreal administration. Furthermore, the in situ-forming implant was found to prolong drug presence in the retina to 30 days following a single administration, confirming that a PLGA-based implant is a viable approach for this drug candidate.

The pursuit of linear dosage in pharmacy: reservoir-based drug delivery systems from macro to micro scale

INTRODUCTION

The pursuit of linear dosage in pharmacy is essential for achieving consistent therapeutic release and enhancing patient compliance. This review provides a comprehensive summary of zero-order drug delivery systems, with a particular focus on reservoir-based systems emanated from different microfabrication technologies.

AREAS COVERED

The consideration of recent advances in drug delivery systems is given to encompass the key areas including the importance of achieving a constant drug release rate for therapeutic applications. Detailed examination of reservoir-based systems, their design, mechanisms of action and materials used are highlighted. By addressing these areas, the discussion aims to provide a thorough understanding of most recent zero-order drug delivery systems, their performance advantages and methods of their manufacturing. To ensure the complete coverage of the explored research area, modern AI-assistant tools were used to find not only the most relevant, but also connected and similar articles.

EXPERT OPINION

Future developments in reservoir-based drug delivery systems are expected to significantly enhance therapeutic effectiveness and patient outcomes through the integration of innovative materials and technologies. The fabrication of intelligent drug delivery systems that utilize sensors and feedback mechanisms can enable real-time monitoring of drug release and patient reactions.

Electrospinning-netting of spider-inspired polycaprolactone/collagen nanofiber-nets incorporated with Propolis extract for enhanced wound healing applications

Nanofibers hold significant promise for wound healing applications, but their potential is limited by their large diameter. To overcome this limitation, the development of nanofibrous systems with refined nanonets (approximately 20 nm in diameter) represents a notable improvement. In this study, a composite of polycaprolactone/collagen (PCLC) nano-fiber/nets (NFNs) was fabricated using benign solvents (acetic acid and formic acid) via the electro-spinning/netting (ESN) technique, harnessing the regenerative potential of collagen as a biological macromolecule. Additionally, to enhance the natural attributes of the NFNs structure, Propolis extract, renowned for its wound healing properties, was incorporated. Five ESN solutions were prepared: PCL, PCLC, PCLC/Pro 5 %, PCLC/Pro 10 %, and PCLC/Pro 15 %. NaCl salt was introduced into all ESN solutions to improve nanonets formation. FE-SEM imaging demonstrated successful nano-net formation in all ESN solutions except for the PCL formulation. The fabricated scaffolds exhibited spider-like nanonets with the addition of collagen and further enhanced nano-net formation with Propolis incorporation. Trunk nanofibers showed filamentous structures without any beads, with an average diameter of 164-728 nm, while the diameter of branched fibers (nanonets) was approximately 20 nm. WVTR values of the NFNs were comparable to commercial dressings such as Tegaderm. The results also demonstrated the potent cytoprotective effects of Propolis-loaded NFNs in a dose-dependent manner. Furthermore, the viability of HFF-2 cells after 72 h of culture on PCLC NFNs significantly increased compared to PCL nanofibers. The highest cell viability was observed in PCLC/Pro 15 % nanofibers after 24, 48, and 72 h of cell culture, indicating the proliferative effect of Propolis extract in nanoformulated form. Additionally, the scaffolds exhibited a hemocompatibility of <3 %, further highlighting their potential in wound healing therapeutics.

Evaluating the protective effects of dexamethasone and electrospun mesh combination on primary human mixed retinal cells under hyperglycemic stress

Chronic inflammation is a leading cause of neurodegeneration and vision loss in hyperglycemia-associated conditions such as diabetic retinopathy. Corticosteroid injections are widely used for treatment but suffer from limitations such as rapid drug clearance, short drug half-lives and frequent administration. While drug release from biomaterial carriers can overcome these shortcomings, evaluating the combined effects of corticosteroids and polymeric matrices under hyperglycemic stress is an important step towards aiding translation. In this study, we investigated the effects of dexamethasone (DEX) and electrospun mesh combination on primary human mixed retinal cells under normal and hyperglycemic culture conditions. DEX-incorporated poly(lactide-co-glycolide) (PLGA) meshes were prepared and characterized for architecture, chemistry, drug distribution and in vitro release. The meshes exhibited cumulative in vitro drug release of 39.5 % over 2 months at a near constant rate. Under normal culture conditions, DEX-PLGA meshes promoted significantly higher viability of mixed retinal cells than the control groups but without adverse phenotypic activation. Under hyperglycemic conditions, DEX supplementation resulted in higher viability than the control, although the highest viability was achieved only when DEX was added to cells cultured on PLGA fibers. The combination of DEX and PLGA fibers also promoted higher mRNA expression of the antioxidant GSH under hyperglycemia. Importantly, the largest reduction in the production of pro-inflammatory cytokines viz., MMP-9, IL-6, IL-8 and VEGF-R1 was observed for the DEX and PLGA combination. Our study reveals a combined effect of DEX and electrospun fibers in combating hyperglycemia-driven pro-inflammatory responses, which can aid the development of DEX-loaded electrospun implants for diabetes-driven retinal conditions.

Silk fibroin-derived electrospun materials for biomedical applications: A review

Electrospinning is a versatile technique for fabricating polymeric fibers with diameters ranging from micro- to nanoscale, exhibiting multiple morphologies and arrangements. By combining silk fibroin (SF) with synthetic and/or natural polymers, electrospun materials with outstanding biological, chemical, electrical, physical, mechanical, and optical properties can be achieved, fulfilling the evolving biomedical demands. This review highlights the remarkable versatility of SF-derived electrospun materials, specifically focusing on their application in tissue regeneration (including cartilage, cornea, nerves, blood vessels, bones, and skin), disease treatment (such as cancer and diabetes), and the development of controlled drug delivery systems. Additionally, we explore the potential future trends in utilizing these nanofibrous materials for creating intelligent biomaterials, incorporating biosensors and wearable sensors for monitoring human health, and also discuss the bottlenecks for its widespread use. This comprehensive overview illuminates the significant impact and exciting prospects of SF-derived electrospun materials in advancing biomedical research and applications.

Application of the oxycodone templated molecular imprinted polymer in adsorption of the drug from human blood plasma as the real biological environment; a joint experimental and density functional theory study

In this project, we have synthesized and used a molecular imprinted polymer (MIP) for adsorption of oxycodone residue from the biological samples. Indeed, this study aims to develop a suitable method for determination of oxycodone drug residue in the human plasma using the common analysis methods. Therefore, the MIP was used for the solid phase extraction (MIP-SPE) approach in order to collect the oxycodone opioid and to concentrate it in the blood plasma samples. The extraction parameters such as adsorption time, pH, and the amount of sorbent in blood plasma were optimized and the capacity of loading amount (LA) for adsorbing it was determined. Moreover, a high performance liquid chromatography (HPLC)-UV detector method was validated and used for analyzing of the mentioned opioid extracted from plasma. The results showed that the limit of detection (LOD), and the limit of quantization (LOQ) for the developed MIP-SPE method were 1.24 ppb, and 3.76 ppb, respectively. Moreover, both of the MIP-, and non-imprinted polymers (NIP)-drug complexes were designed and were then optimized by the density functional theory (DFT) method. The results showed that the theoretical calculations supported the experimental data, confirming the favorability of adsorption of the drug by MIP compared to NIP.

Electrospun fiber-based strategies for controlling early innate immune cell responses: Towards immunomodulatory mesh designs that facilitate robust tissue repair

Electrospun fibrous meshes are widely used for tissue repair due to their ability to guide a host of cell responses including phenotypic differentiation and tissue maturation. A critical factor determining the eventual biological outcomes of mesh-based regeneration strategies is the early innate immune response following implantation. The natural healing process involves a sequence of tightly regulated, temporally varying and delicately balanced pro-/anti-inflammatory events which together promote mesh integration with host tissue. Matrix designs that do not account for the immune milieu can result in dysregulation, chronic inflammation and fibrous capsule formation, thus obliterating potential therapeutic outcomes. In this review, we provide systematic insights into the effects of specific fiber/mesh properties and mechanical stimulation on the responses of early innate immune modulators viz., neutrophils, monocytes and macrophages. We identify matrix characteristics that promote anti-inflammatory immune phenotypes, and we correlate such responses with pro-regenerative in vivo outcomes. We also discuss recent advances in 3D fabrication technologies, bioactive functionalization approaches and biomimetic/bioinspired immunomodulatory mesh design strategies for tissue repair and wound healing. The mechanobiological insights and immunoregulatory strategies discussed herein can help improve the translational outcomes of fiber-based regeneration and may also be leveraged for intervention in degenerative diseases associated with dysfunctional immune responses. STATEMENT OF SIGNIFICANCE: The crucial role played by immune cells in promoting biomaterial-based tissue regeneration is being increasingly recognized. In this review focusing on the interactions of innate immune cells (primarily neutrophils, monocytes and macrophages) with electrospun fibrous meshes, we systematically elucidate the effects of the fiber microenvironment and mechanical stimulation on biological responses, and build upon these insights to inform the rational design of immunomodulatory meshes for effective tissue repair. We discuss state-of-the-art fabrication methods and mechanobiological advances that permit the orchestration of temporally controlled phenotypic switches in immune cells during different phases of healing. The design strategies discussed herein can also be leveraged to target several complex autoimmune and inflammatory diseases.