Preparation of emulsifying wax/glyceryl monooleate nanoparticles and evaluation as a delivery system for repurposing simvastatin in bone regeneration

Biomaterial-Based Additive Manufactured Composite/Scaffolds for Tissue Engineering and Regenerative Medicine: A Comprehensive Review

Additive manufacturing (AM), also referred to as three-dimensional printing/printed (3DP), has emerged as a transformative approach in the current design and manufacturing of various biomaterials for the restoration of damaged tissues inside the body. This advancement has greatly aided the development of customized biomedical devices including implants, prosthetics, and orthotics that are specific to the patients. In tissue engineering (TE), AM enables the fabrication of complex structures that promote desirable cellular responses in the regeneration of tissues. Since the choice of biomaterials plays a vital role in scaffold performance as well as cellular responses, meticulous material selection is essential in optimizing the functionality of scaffolds. These scaffolds often possess certain characteristics such as biodegradability, biocompatibility, biomimicry, and porous structure. To this end, polymers such as chitosan, collagen, alginate, hyaluronic acid, polyglycolic acid, polylactic acid, and polycaprolactone have been extensively investigated in the fabrication of tissue-engineered scaffolds. Furthermore, combinations of biomaterials are also utilized to further enhance the scaffolds' performance and functionality. This review discusses the principle of AM and explores recent advancements in AM technologies in the development of TE and regenerative medicine. In addition, the applications of 3DP, polymer-based scaffolds will be highlighted.

Potential of Chitosan/Gelatin-Based Nanofibers in Delivering Drugs for the Management of Varied Complications: A Review

Drug delivery systems have revolutionized traditional drug administration methods by addressing various challenges, such as enhancing drug solubility, prolonging effectiveness, minimizing adverse effects, and preserving potency. Nanotechnology-based drug delivery systems, particularly nanoparticles (NPs) and nanofibers (NFs), have emerged as promising solutions for biomedicine delivery. NFs, with their ability to mimic the porous and fibrous structures of biological tissues, have garnered significant interest in drug-delivering applications. Biopolymers such as gelatin (Ge) and chitosan (CH) have gained much more attention due to their biocompatibility, biodegradability, and versatility in biomedical applications. CH exhibits exceptional biocompatibility, anti-bacterial activity, and wound healing capabilities, whereas Ge provides good biocompatibility and cell adhesion properties. Ge/CH-based NFs stimulate cellular connections and facilitate tissue regeneration owing to their structural resemblance to the extracellular matrix. This review explores the additive methods of preparation, including electrospinning, force pinning, and template synthesis, focusing on electrospinning and the factors influencing the fiber structure. The properties of Ge and CH, their role in drug release, formulation strategies, and characterization techniques for electrospun fibers are discussed. Furthermore, this review addresses applications in delivering active moieties in the management of orthopedics and wound healing with regulatory considerations, along with challenges related to them. Thus, the review aims to provide a comprehensive overview of the potential of Ge/CH-based NFs for drug delivery and biomedical applications.

Self-Assembled Nanoscale Materials for Neuronal Regeneration: A Focus on BDNF Protein and Nucleic Acid Biotherapeutic Delivery

Enabling challenging applications of nanomedicine and precision medicine in the treatment of neurodegenerative disorders requires deeper investigations of nanocarrier-mediated biomolecular delivery for neuronal targeting and recovery. The successful use of macromolecular biotherapeutics (recombinant growth factors, antibodies, enzymes, synthetic peptides, cell-penetrating peptide–drug conjugates, and RNAi sequences) in clinical developments for neuronal regeneration should benefit from the recent strategies for enhancement of their bioavailability. We highlight the advances in the development of nanoscale materials for drug delivery in neurodegenerative disorders. The emphasis is placed on nanoformulations for the delivery of brain-derived neurotrophic factor (BDNF) using different types of lipidic nanocarriers (liposomes, liquid crystalline or solid lipid nanoparticles) and polymer-based scaffolds, nanofibers and hydrogels. Self-assembled soft-matter nanoscale materials show favorable neuroprotective characteristics, safety, and efficacy profiles in drug delivery to the central and peripheral nervous systems. The advances summarized here indicate that neuroprotective biomolecule-loaded nanoparticles and injectable hydrogels can improve neuronal survival and reduce tissue injury. Certain recently reported neuronal dysfunctions in long-COVID-19 survivors represent early manifestations of neurodegenerative pathologies. Therefore, BDNF delivery systems may also help in prospective studies on recovery from long-term COVID-19 neurological complications and be considered as promising systems for personalized treatment of neuronal dysfunctions and prevention or retarding of neurodegenerative disorders.

Lipid-Based Drug Delivery Systems in Regenerative Medicine

The most important goal of regenerative medicine is to repair, restore, and regenerate tissues and organs that have been damaged as a result of an injury, congenital defect or disease, as well as reversing the aging process of the body by utilizing its natural healing potential. Regenerative medicine utilizes products of cell therapy, as well as biomedical or tissue engineering, and is a huge field for development. In regenerative medicine, stem cells and growth factor are mainly used; thus, innovative drug delivery technologies are being studied for improved delivery. Drug delivery systems offer the protection of therapeutic proteins and peptides against proteolytic degradation where controlled delivery is achievable. Similarly, the delivery systems in combination with stem cells offer improvement of cell survival, differentiation, and engraftment. The present review summarizes the significance of biomaterials in tissue engineering and the importance of colloidal drug delivery systems in providing cells with a local environment that enables them to proliferate and differentiate efficiently, resulting in successful tissue regeneration.

Targeting Drug Delivery in the Elderly: Are Nanoparticles an Option for Treating Osteoporosis?

Nanoparticles bearing specific targeting groups can, in principle, accumulate exclusively at lesion sites bearing target molecules, and release therapeutic agents there. However, practical application of targeted nanoparticles in the living organism presents challenges. In particular, intravasally applied nanoparticles encounter physical and physiological barriers located in blood vessel walls, blocking passage from the blood into tissue compartments. Whereas small molecules can pass out of the blood, nanoparticles are too large and need to utilize physiological carriers enabling passage across endothelial walls. The issues associated with crossing blood-tissue barriers have limited the usefulness of nanoparticles in clinical applications. However, nanoparticles do not encounter blood-tissue barriers if their targets are directly accessible from the blood. This review focuses on osteoporosis, a disabling and common disease for which therapeutic strategies are limited. The target sites for therapeutic agents in osteoporosis are located in bone resorption pits, and these are in immediate contact with the blood. There are specific targetable biomarkers within bone resorption pits. These present nanomedicine with the opportunity to treat a major disease by use of simple nanoparticles loaded with any of several available effective therapeutics that, at present, cannot be used due to their associated side effects.

Simvastatin-Incorporated Drug Delivery Systems for Bone Regeneration

Local drug delivery systems composed of biomaterials and osteogenic substances provide promising strategies for the reconstruction of large bone defects. In recent years, simvastatin has been studied extensively for its pleiotropic effects other than lowering of cholesterol, including its ability to induce osteogenesis and angiogenesis. Accordingly, several studies of simvastatin incorporated drug delivery systems have been performed to demonstrate the feasibility of such systems in enhancing bone regeneration. Therefore, this review explores the molecular mechanisms by which simvastatin affects bone metabolism and angiogenesis. The simvastatin concentrations that promote osteogenic differentiation are analyzed. Furthermore, we summarize and discuss a variety of simvastatin-loaded drug delivery systems that use different loading methods and materials. Finally, current shortcomings of and future development directions for simvastatin-loaded drug delivery systems are summarized. This review provides various advanced design strategies for simvastatin-incorporated drug delivery systems that can enhance bone regeneration.

Dual-Effective Chronic Wounds Management System through a Monoglyceride Binary Blend Matrix Based Thermal-Responsive Phase-Transition Substrate

A new monoglyceride-based heat-sensitive substrate is proposed, for the first time, as a wound management system. First, an appropriate portion of glyceryl monooleate (GMO) and glyceryl monostearate (GMS) is mixed to provide a thermal phase responsive matrix (GMO-GMS, GG). Subsequently, to improve the photothermal responsive and antibacterial performance, silver nanoparticles (Ag) decorated reduced graphene oxide (rGO) nanocomposite (rGO-Ag) is added to the GG matrix to obtain (GG-rGO-Ag). According to the systematic studies from uninfected, infected, and diabetic wound models, by applying near infrared (NIR) laser, the phase change of GG-rGO-Ag can be triggered to release Ag on demand for sterilization. More importantly, this smart GG substrate can also promote the production of vascular endothelial growth factor protein, thus serving as a NIR defined mufti-effective wound management system.

Overcoming barriers confronting application of protein therapeutics in bone fracture healing

Bone fracture is a major contributor to debilitation and death among patients with bone diseases. Thus, osteogenic protein therapeutics and their delivery to bone have been extensively researched as strategies to accelerate fracture healing. To prevent morbidity and mortality of fractures, which occur frequently in the aging population, there is a critical need for development of first-line therapeutics. Bone morphogenic protein-2 (BMP-2) has been at the forefront of bone regeneration research for its potent osteoinduction, despite safety concerns and biophysiological obstacles of delivery to bone. However, continued pursuit of osteoinductive proteins as a therapeutic option is largely aided by drug delivery systems, playing an imperative role in enhancing safety and efficacy. In this work, we highlighted several types of drug delivery platforms and their biomaterials, to evaluate the suitability in overcoming challenges of therapeutic protein delivery for bone regeneration. To showcase the clinical considerations for each type of platform, we have assessed the most common route of administration strategies for bone regeneration, classifying the platforms as implantable or injectable. Additionally, we have analyzed the commonly utilized models and methodology for safety and efficacy evaluation of these osteogenic protein-loaded systems, to present clinical opinions for future directions of research in this field. It is hoped that this review will promote research and development of clinically translatable osteogenic protein therapeutics, while targeting first-line treatment status for achieving desired outcomes of fracture healing. Graphical abstract.

Delivery Systems as Vital Tools in Drug Repurposing

The process of developing an old drug for new indications is now a widely accepted strategy of shortening drug development time, reducing drug costs, and improving drug availability, especially for rare and neglected diseases. In this mini-review, we highlighted the impact of drug delivery systems in the fulfillment of crucial aspects of drug repurposing such as (i) maximizing the repurposed drug effects on a new target, (ii) minimizing off-target effects, (iii) modulating the release profiles of drug at the site of absorption, (iv) modulating the pharmacokinetics/in vivo biodistribution of the repurposed drug, (v) targeting/modulating drug retention at the sites of action, and (vi) providing a suitable platform for therapeutic application of combination drugs.