A Nanofiber Sheet Incorporating Vitamin B12 Promotes Nerve Regeneration in a Rat Neurorrhaphy Model

Methylcobalamin-containing nanofiber sheets have better neuroprotective effects than small intestinal submucosa sheets

Postoperative adhesion around nerves sometimes results in sensory and motor dysfunctions. To prevent these disorders, we have developed an electrospun nanofiber sheet incorporating methylcobalamin (MeCbl), an active form of vitamin B12 with anti-inflammatory and neuroregenerative effects. This study aimed to investigate the neuroprotective effects of MeCbl sheets against postoperative adhesion and to compare the effects of MeCbl sheets with those of porcine small intestinal submucosa (SIS) sheets using a rat sciatic nerve adhesion model. Behavioral and electrophysiological analyses showed superior results in the MeCbl sheet group compared with those in the untreated group, all of which were non-inferior to the SIS sheet group. Histological analysis revealed less collagen and inflammatory cell invasion into the nerve parenchyma and a higher number of residual axons and myelination rate in the MeCbl sheet group than in the untreated group. Moreover, the MeCbl sheet group was superior to the SIS sheet group in terms of the myelination rate and decreased number of infiltrating macrophages. Furthermore, the distribution of residual axons by diameter revealed that the MeCbl sheet group had thicker axons than the SIS sheet group. The use of MeCbl sheets may represent a novel approach for preventing secondary nervous system impairment following inflammation.

Electrospun drug-loaded scaffolds for nervous system repair

Nervous system injuries, encompassing peripheral nerve injury (PNI), spinal cord injury (SCI), and traumatic brain injury (TBI), present significant challenges to patients' wellbeing. Traditional treatment approaches have limitations in addressing the complexity of neural tissue regeneration and require innovative solutions. Among emerging strategies, implantable materials, particularly electrospun drug-loaded scaffolds, have gained attention for their potential to simultaneously provide structural support and controlled release of therapeutic agents. This review provides a thorough exploration of recent developments in the design and application of electrospun drug-loaded scaffolds for nervous system repair. The electrospinning process offers precise control over scaffold characteristics, including mechanical properties, biocompatibility, and topography, crucial for creating a conducive environment for neural tissue regeneration. The large surface area of the resulting fibrous networks enhances biomolecule attachment, influencing cellular behaviors such as adhesion, proliferation, and migration. Polymeric electrospun materials demonstrate versatility in accommodating a spectrum of therapeutics, from small molecules to proteins. This enables tailored interventions to accelerate neuroregeneration and mitigate inflammation at the injury site. A critical aspect of this review is the examination of the interplay between structural properties and pharmacological effects, emphasizing the importance of optimizing both aspects for enhanced therapeutic outcomes. Drawing upon the latest advancements in the field, we discuss the promising outcomes of preclinical studies using electrospun drug-loaded scaffolds for nervous system repair, as well as future perspectives and considerations for their design and implementation. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Emerging Technologies.

A novel transdermal delivery route for energy supplements: Electrospun chitosan/polyvinyl alcohol nanofiber patches loaded with vitamin B12

Nanofibrous patches have attracted much attention as a solution to resolve drug delivery challenges. In this study, vitamin B₁₂- loaded polyvinyl alcohol (PVA)/chitosan (Cs) nanofiber patch (NFP) was electrospun and cross-linked by glutaraldehyde (GA). The physicochemical properties of the nanofiber patches were assessed by morphological studies, FTIR analysis, hydrophilicity test, mechanical tests, and in-vitro evaluations including biodegradability, MTT assay, and cumulative release test of vitamin. In-vivo studies were also carried out by measuring vitamin B₁₂ levels in the bloodstream and conducting histopathology studies on the animal models. The results showed that the mean diameter of Cs/PVA/B₁₂ and cross-linked patch were approximately 207 and 256 nm, respectively. Cross-linking of NFP led to the lower, slower, and more continuous release of the vitamin with a slight decrease in biodegradability, and an increase in the mechanical properties of the nanofiber patches. Furthermore, the cytocompatibility assay, MTT, and in vivo results revealed no cytotoxicity of Cs/PVA/B₁₂ NFP towards L929 cell line. No lesion or tissue damage was observed in the skin tissue of the animal models wearing these skin patches. Therefore, B₁₂-loaded NFP can be introduced as a potential candidate for commercial transdermal routes.

Efficacy of Nanofiber Sheets Incorporating Lenvatinib in a Hepatocellular Carcinoma Xenograft Model

Lenvatinib has a high response rate in unresectable advanced hepatocellular carcinoma (HCC). In this study, we investigated whether lenvatinib-incorporating poly(ε-caprolactone) sheets (lenvatinib sheets) as a drug delivery system (DDS) exerted antitumor effects in a murine HCC model. The lenvatinib sheets were designed for sustained release of approximately 1 mg lenvatinib for 14 days. For 14 days, 1 mg lenvatinib was orally administered to mice. Then, we compared the antitumor effects of lenvatinib sheets with those of oral lenvatinib. The tumor volume, body weight, and serum lenvatinib level were measured for 14 days. A peritoneal dissemination model was established to examine the survival prolongation effect of the lenvatinib sheets. Tumor growth was significantly inhibited in the lenvatinib sheet group compared with that in the no treatment and oral groups. The antitumor effect was significantly higher in the lenvatinib sheet group. Regardless of the insertion site, the serum lenvatinib levels were maintained and showed similar antitumor effects. The mitotic index was significantly inhibited in the lenvatinib sheet group compared with that in the control group. Furthermore, lenvatinib sheets improved the 30-day survival. Lenvatinib sheets showed sufficient antitumor effects and may serve as an effective novel DDS for advanced HCC.