Composite nanofibers incorporating alpha lipoic acid and atorvastatin provide neuroprotection after peripheral nerve injury in rats

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.

Chlorogenic acid releasing microspheres enhanced electrospun conduits to promote peripheral nerve regeneration

Chlorogenic acid (CGA) has been confirmed as a polyphenol, and existing research has suggested the high bioactivity of CGA for therapeutic effects on a wide variety of diseases. Despite the existing reports of anti-inflammatory, antioxidant, and neuroprotective effects of CGA, the role and mechanism of CGA in facilitating the regeneration of peripheral nerve defects have been rarely investigated. Herein, a biodegradable polycaprolactone (PCL) conduit with embedded CGA-releasing GelMA microspheres (CGM/PCL) was successfully prepared and used for repairing a rate model with sciatic nerve defects. CGM and CGM/PCL conduits displayed high in vitro biocompatibility and can support the growth of cells for nerve regeneration. Furthermore, CGM/PCL conduits displayed high performance which is close to that of autologous nerve grafts in promoting in vivo PNI regeneration, compared with PCL conduits. The sciatic nerve functional index analysis, electrophysiological examination, and immunological analysis performed to evaluate the functional recovery of the injurious sciatic nerve of rats have indeed proved the favorable effects of CGM/PCL conduits. The result of this study not only aimed to explore CGA's contribution to nerve regeneration but also provided a new strategy for designing and preparing functional NGCs for PNI treatment.

An overview on nanoplatforms for statins delivery: Perspectives for safe and effective therapy

Statins are the most widely used pharmacological agents for reducing blood cholesterol levels and treating atherosclerotic cardiovascular diseases. Most of the statins' derivatives have been limited by water solubility, bioavailability, and oral absorption, which has led to adverse effects on several organs, especially at high doses. As an approach to reducing statin intolerance, achieving a stable formulation with improved efficacy and bioavailability at low doses has been suggested. Nanotechnology-based formulations may provide a therapeutic benefit over traditional formulations in terms of potency and biosafety. Nanocarriers can provide tailored delivery platforms for statins, thereby enhancing the localized biological effects and lowering the risk of undesired side effects while boosting statin's therapeutic index. Furthermore, tailored nanoparticles can deliver the active cargo to the desired site, which culminates in reducing off-targeting and toxicity. Nanomedicine could also provide opportunities for therapeutic methods by personalized medicine. This review delves into the existing data on the potential improvement of statin therapy using nano-formulations.

A grooved conduit combined with decellularized tissues for peripheral nerve regeneration

Peripheral nerve injury (PNI) is a common and severe clinical disease worldwide, which leads to a poor prognosis because of the complicated treatments and high morbidity. Autologous nerve grafting as the gold standard still cannot meet the needs of clinical nerve transplantation because of its low availability and limited size. The development of artificial nerve conduits was led to a novel direction for PNI treatment, while most of the currently developed artificial nerve conduits was lack biochemical cues to promote nerve regeneration. In this study, we designed a novel composite neural conduit by inserting decellularized the rat sciatic nerve or kidney in a poly (lactic-co-glycolic acid) (PLGA) grooved conduit. The nerve regeneration effect of all samples was analyzed using rat sciatic nerve defect model, where decellularized tissues and grooved PLGA conduit alone were used as controls. The degree of nerve regeneration was evaluated using the motor function, gastrocnemius recovery, and morphological and histological assessments suggested that the combination of a grooved conduit with decellularized tissues significantly promoted nerve regeneration compared with decellularized tissues and PLGA conduit alone. It is worth to note that the grooved conduits containing decellularized nerves have a promotive effect similar to that of autologous nerve grafting, suggesting that it could be an artificial nerve conduit used for clinical practice in the future.

Molecular and Computational Analysis Identify Statins as Selective Inhibitors of Human Butyrylcholinesterase

Cholinesterase enzyme family consists of acetylcholinesterase (AChE, 3.1.1.7), the major enzyme responsible for hydrolysis of acetylcholine at cholinergic synapses, and butyrylcholinesterase (BChE, 3.1.1.8) a detoxification enzyme of plasma. Statins are cholesterol-lowering medications utilized as protective medicaments in stroke and Alzheimer's disease, which cholinesterases are associated with. Thus, in this study, we characterized the inhibitory effects and mechanisms of common statins, rosuvastatin, atorvastatin, simvastatin and lovastatin, on human erythrocyte AChE and purified serum BChE using in vitro and in silico methods. Kinetic assays identified statins as selective non-competitive inhibitors of human serum BChE. The IC₅₀ and K_m values were found as 194.7 ± 55.2 µM and 1.03 ± 0.2 µM for rosuvastatin, 492.5 ± 55.1 µM and 7.2 ± 0.3 µM for atorvastatin, 14.2 ± 0.3 µM and 202.7 ± 23.2 µM for lovastatin, and 17.6 ± 0.1 µM and 207.2 ± 13.2 µM for simvastatin, respectively. The compounds did not display considerable inhibition against AChE. Molecular docking predicted good affinity and strong interactions with the BChE active site for atorvastatin and rosuvastatin. Current study identifies rosuvastatin as the most specific and selective inhibitor of human BChE among the tested statins. As selective inhibitors of BChE statins have the potential to be re-evaluated as medicaments due to their pleiotropic effects.

Alpha-Lipoic Acid as an Antioxidant Strategy for Managing Neuropathic Pain

Neuropathic pain (NP) is the most prevalent and debilitating form of chronic pain, caused by injuries or diseases of the somatosensory system. Since current first-line treatments only provide poor symptomatic relief, the search for new therapeutic strategies for managing NP is an active field of investigation. Multiple mechanisms contribute to the genesis and maintenance of NP, including damage caused by oxidative stress. The naturally occurring antioxidant alpha-lipoic acid (ALA) is a promising therapeutic agent for the management of NP. Several pre-clinical in vitro and in vivo studies as well as clinical trials demonstrate the analgesic potential of ALA in the management of NP. The beneficial biological activities of ALA are reflected in the various patents for the development of ALA-based innovative products. This review demonstrates the therapeutic potential of ALA in the management of NP by discussing its analgesic effects by multiple antioxidant mechanisms as well as the use of patented ALA-based products and how technological approaches have been applied to enhance ALA's pharmacological properties.

A review of the diet, nutrients, and supplementation potential for the outcome augmentation in surgical treatment of peripheral nerve injuries

OBJECTIVE

Although the studies have shown the beneficial effects of diet, nutrition, and supplementation as an independent treatment modality, their roles are underestimated in the treatment of peripheral nerve injuries. This is in great part due to the development of efficient nerve repair techniques, combined with physical treatment and stimulation. To achieve the best possible functional recovery diet, nutrition, and supplementation should be implemented within a multidisciplinary approach. The aim of the study is to provide insight into the potentially beneficial effects of diet, nutrients, and supplementation, in the limitation of nerve damage and augmentation of the functional recovery after surgery in a review of human and animal studies.

METHODS

The data relating to the diet, nutrients, and supplementation effects on peripheral nerve injuries and their treatment was extracted from the previously published literature.

RESULTS

General balanced diet as well as obesity influence the initial nerve features prior to the injury. In the period following the injury, neuroprotective agents demonstrated beneficial effects prior to surgery, and immediately after the injury, while those potentiating nerve regeneration may be used after the surgical repair to complement the physical treatment and stimulation for improved functional recovery.

CONCLUSIONS

Standardized diet, nutrition, and supplementation recommendations and protocols may be of great importance for better nerve regeneration and functional recovery as a part of the multidisciplinary approach to achieve the best possible results in surgically treated patients with peripheral nerve injuries in the future.

Peripheral neuropathy: A neglected cause of disability in COPD - A narrative review

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory syndrome with systemic involvement leading to various cardiovascular, metabolic, and neurological comorbidities. It is well known that conditions associated with oxygen deprivation and metabolic disturbance are associated with polyneuropathy, but current data regarding the relationship between COPD and peripheral nervous system pathology is limited. This review summarizes the available data on the association between COPD and polyneuropathy, including possible pathophysiological mechanisms such as the role of hypoxia, proinflammatory state, and smoking in nerve damage; the role of cardiovascular and metabolic comorbidities, as well as the diagnostic methods and screening tools for identifying polyneuropathy. Furthermore, it outlines the available options for managing and preventing polyneuropathy in COPD patients. Overall, current data suggest that optimal screening strategies to diagnose polyneuropathy early should be implemented in COPD patients due to their relatively common association and the additional burden of polyneuropathy on quality of life.

Atractylenolide III ameliorates spinal cord injury in rats by modulating microglial/macrophage polarization

Background

Inflammatory reactions induced by spinal cord injury (SCI) are essential for recovery after SCI. Atractylenolide III (ATL‐III) is a natural monomeric herbal bioactive compound that is mainly derived in Atractylodes macrocephala Koidz and has anti‐inflammatory and neuroprotective effects.

Objective

Here, we speculated that ATL‐III may ameliorate SCI by modulating microglial/macrophage polarization. In the present research, we focused on investigating the role of ATL‐III on SCI in rats and explored the potential mechanism.

Methods

The protective and anti‐inflammatory effects of ATL‐III on neuronal cells were examined in a rat SCI model and lipopolysaccharide (LPS)‐stimulated BV2 microglial line. The spinal cord lesion area, myelin integrity, and surviving neurons were assessed by specific staining. Locomotor function was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale, grid walk test, and footprint test. The activation and polarization of microglia/macrophages were assessed by immunohistofluorescence and flow cytometry. The expression of corresponding inflammatory factors from M1/M2 and the activation of relevant signaling pathways were assessed by Western blotting.

Results

ATL‐III effectively improved histological and functional recovery in SCI rats. Furthermore, ATL‐III promoted the transformation of M1 into M2 and attenuated the activation of microglia/macrophages, further suppressing the expression of corresponding inflammatory mediators. This effect may be partly mediated by inhibition of neuroinflammation through the NF‐κB, JNK MAPK, p38 MAPK, and Akt pathways.

Conclusion

This study reveals a novel effect of ATL‐III in the regulation of microglial/macrophage polarization and provides initial evidence that ATL‐III has potential therapeutic benefits in SCI rats.

Advances in Electrospun Hybrid Nanofibers for Biomedical Applications

Electrospun hybrid nanofibers, based on functional agents immobilized in polymeric matrix, possess a unique combination of collective properties. These are beneficial for a wide range of applications, which include theranostics, filtration, catalysis, and tissue engineering, among others. The combination of functional agents in a nanofiber matrix offer accessibility to multifunctional nanocompartments with significantly improved mechanical, electrical, and chemical properties, along with better biocompatibility and biodegradability. This review summarizes recent work performed for the fabrication, characterization, and optimization of different hybrid nanofibers containing varieties of functional agents, such as laser ablated inorganic nanoparticles (NPs), which include, for instance, gold nanoparticles (Au NPs) and titanium nitride nanoparticles (TiNPs), perovskites, drugs, growth factors, and smart, inorganic polymers. Biocompatible and biodegradable polymers such as chitosan, cellulose, and polycaprolactone are very promising macromolecules as a nanofiber matrix for immobilizing such functional agents. The assimilation of such polymeric matrices with functional agents that possess wide varieties of characteristics require a modified approach towards electrospinning techniques such as coelectrospinning and template spinning. Additional focus within this review is devoted to the state of the art for the implementations of these approaches as viable options for the achievement of multifunctional hybrid nanofibers. Finally, recent advances and challenges, in particular, mass fabrication and prospects of hybrid nanofibers for tissue engineering and biomedical applications have been summarized.

PEG-interpenetrated genipin-crosslinked dual-sensitive hydrogel/nanostructured lipid carrier compound formulation for topical drug administration

PEG-interpenetrated dual-sensitive hydrogels that load nano lipid carrier (NLC) were researched and developed for topical drug administration. Natural antioxidant α-lipoic acid (ALA) was selected as our model drug. The α-lipoic acid (ALA) nano lipid carrier was successfully prepared by hot melt emulsification and ultrasonic dispersion method, and the physicochemical properties of the nano lipid carrier were investigated, including morphology, particle distribution, polydispersity coefficient, zeta potential and encapsulation efficiency. Carboxymethyl chitosan and poloxamer 407 contributed to pH- and temperature-sensitive properties in the hydrogel, respectively. Natural non-toxic cross-linking agent genipin reacted with carboxymethyl chitosan to form the hydrogel. Poly ethylene glycol (PEG), a polymer compound with good water solubility and biocompatibility, interpenetrated the hydrogel and influenced the mechanical strength and drug release behaviour. FI-IR test verified the successful synthesis of the hydrogel. The rheological parameters indicated that the mechanical strength of the hydrogel was positively correlated with the amount of PEG, and the in vitro dissolution profiles demonstrated that the increasement of PEG could accelerate the drug release rate. The compatibility of the drug delivery system was verified with cells and mice model. Topical delivery of ALA in solution, NLC and NLC-gel was investigated in-vitro.

Harnessing Therapeutic Potentials of Statins Using Nanofibrous Carriers

Statins are a wide category of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor drugs extensively prescribed for hypercholesterolemia. In fact, many studies showed beneficial effects of these agents on a variety of related illnesses, which include increased atherosclerotic plaque stability, decreased proliferation of vascular smooth muscle, platelet aggregation, the dampening of vascular inflammation, and also anabolic effects on bone tissue. Therefore, these drugs are considered as pleiotropic agents having different clinical applications other than those for which they were initially developed. Controlled drug delivery is an efficient way of delivery in tissue engineering. Amongst different controlled release formulations, nanofibers are a novel, alternative, widely used agent because of their unique properties. These include their sustained release of drug, a high drug-loading capacity, flexible shapes with a high surface-to-volume ratio, and superior porosity. Electrospinning is an economic and a simple method employed to produce nanofibers. In this report, studies related to statin nanofiber applications have been reviewed and their results have been summarized. Four different applications of statin nanofibers have been reported, including bone generation, endothelial stenosis and thrombosis, peripheral nerve injury, and anti-inflammatory action. Studies carried out both in vitro and in vivo showed effectiveness of statins in bone healing, aneurysm, and the healing of sciatic nerve injury. In addition, statins showed apoptosis effects and anti-inflammatory effects, with dose-dependent reduction of IL-6 and dose-independent reduction of TNF-α. Despite these promising results, validation via clinical trials is yet to be performed. The scope of statins in their pleiotropic range of actions is still not completely explored, and studies are still needed to enlighten different useful aspects of such drugs.