Nano-carrier mediated co-delivery of methyl prednisolone and minocycline for improved post-traumatic spinal cord injury conditions in rats

Inflammation-Targeted Drug Delivery Strategies via Albumin-Based Systems

Albumin, being the most abundant serum protein, has the potential to significantly enhance the physicochemical properties of therapeutic payloads, thereby improving their pharmacological effects. Apart from its passive transport via the enhanced permeability and retention effect, albumin can actively accumulate in tumor microenvironments or inflammatory tissues via receptor-mediated processes. This unique property makes albumin a promising scaffold for targeted drug delivery. This review focuses on exploring different delivery strategies that combine albumin with drug payloads to achieve targeted therapy for inflammatory diseases. Also, albumin-derived therapeutic products on the market or undergoing clinical trials in the past decade have been summarized to gain insight into the future development of albumin-based drug delivery systems. Given the involvement of inflammation in numerous diseases, drug delivery systems utilizing albumin demonstrate remarkable advantages, including enhanced properties, improved in vivo behavior and efficacy. Albumin-based drug delivery systems have been demonstrated in clinical trials, while more advanced strategies for improving the capacity of drug delivery systems with the help of albumin remain to be discovered. This could pave the way for biomedical applications in more effective and precise treatments.

Reviewing particulate delivery systems loaded with repurposed tetracyclines - From micro to nanoparticles

Tetracyclines (TCs) are a class of broad-spectrum antibacterial agents recognized for their multifaceted properties, including anti-inflammatory, angiogenic and osteogenic effects. This versatility positions them as suitable candidates for drug repurposing, benefitting from well-characterized safety and pharmacological profiles. In the attempt to explore both their antibacterial and pleiotropic effects locally, innovative therapeutic strategies were set on engineering tetracycline-loaded micro and nanoparticles to tackle a vast number of clinical applications. Moreover, the conjoined drug carrier can function as an active component of the therapeutic approach, reducing off-target effects and accumulation, synergizing to an improvement of the therapeutic efficacy. In this comprehensive review we will critically evaluate recent advances involving the use of tetracyclines loaded onto micro- or nanoparticles, intended for biomedical applications, and discuss emerging approaches and current limitations associated with these drug carriers. Owing to their distinctive physical, chemical, and biological properties, these novel carriers have the potential to become a platform technology in personalized regenerative medicine and other therapeutic applications.

Spinal Cord-Gut-Immune Axis and its Implications Regarding Therapeutic Development for Spinal Cord Injury

Spinal cord injury (SCI) affects ∼1,300,000 people living in the United States. Most research efforts have been focused on reversing paralysis, as this is arguably the most defining feature of SCI. The damage caused by SCI, however, extends past paralysis and includes other debilitating outcomes including immune dysfunction and gut dysbiosis. Recent efforts are now investigating the pathophysiology of and developing therapies for these more distal manifestations of SCI. One exciting avenue is the spinal cord-gut-immune axis, which proposes that gut dysbiosis amplifies lesion inflammation and impairs SCI recovery. This review will highlight the most recent findings regarding gut and immune dysfunction following SCI, and discuss how the central nervous system (CNS), gut, and immune system all coalesce to form a bidirectional axis that can impact SCI recovery. Finally, important considerations regarding how the spinal cord-gut-immune axis fits within the larger framework of therapeutic development (i.e., probiotics, fecal transplants, dietary modifications) will be discussed, emphasizing the lack of interdepartmental investigation and the missed opportunity to maximize therapeutic benefit in SCI.

Biomimetic engineered approaches for neural tissue engineering: Spinal cord injury

The healing process for spinal cord injuries is complex and presents many challenges. Current advances in nerve regeneration are based on promising tissue engineering techniques, However, the chances of success depend on better mimicking the extracellular matrix (ECM) of neural tissue and better supporting neurons in a three-dimensional environment. The ECM provides excellent biological conditions, including desirable morphological features, electrical conductivity, and chemical compositions for neuron attachment, proliferation and function. This review outlines the rationale for developing a construct for neuron regrowth in spinal cord injury using appropriate biomaterials and scaffolding techniques.

Recent advances in nanomaterials for the treatment of spinal cord injury

Spinal cord injuries (SCIs) are devastating. In SCIs, a powerful traumatic force impacting the spinal cord results in the permanent loss of nerve function below the injury level, leaving the patient paralyzed and wheelchair-bound for the remainder of his/her life. Unfortunately, clinical treatment that depends on surgical decompression appears to be unable to handle damaged nerves, and high-dose methylprednisolone-based therapy is also associated with problems, such as infection, gastrointestinal bleeding, femoral head necrosis, obesity, and hyperglycemia. Nanomaterials have opened new avenues for SCI treatment. Among them, performance-based nanomaterials derived from a variety of materials facilitate improvements in the microenvironment of traumatic injury and, in some cases, promote neuron regeneration. Nanoparticulate drug delivery systems enable the optimization of drug effects and drug bioavailability, thus contributing to the development of novel treatments. The improved efficiency and accuracy of gene delivery will also benefit the exploration of SCI mechanisms and the understanding of key genes and signaling pathways. Herein, we reviewed different types of nanomaterials applied to the treatment of SCI and summarized their functions and advantages to provide new perspectives for future clinical therapies.

The potential use of tetracyclines in neurodegenerative diseases and the role of nano-based drug delivery systems

Neurodegenerative diseases are still a challenge for effective treatments. The high cost of approved drugs, severity of side effects, injection site pain, and restrictions on drug delivery to the Central Nervous System (CNS) can overshadow the management of these diseases. Due to the chronic and progressive evolution of neurodegenerative disorders and since there is still no cure for them, new therapeutic strategies such as the combination of several drugs or the use of existing drugs with new therapeutic applications are valuable strategies. Tetracyclines are traditionally classified as antibiotics. However, in this class of drugs, doxycycline and minocycline exhibit also anti-inflammatory effects by inhibiting microglia/macrophages. Hence, they have been studied as potential agents for the treatment of neurodegenerative diseases. The results of in vitro and in vivo studies confirm the effective role of these two drugs as anti-inflammatory agents in experimentally induced models of neurodegenerative diseases. In clinical studies, satisfactory results have been obtained in Multiple sclerosis (MS) but not yet in other disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), or Amyotrophic lateral sclerosis (ALS). In recent years, researchers have developed and evaluated nanoparticulate drug delivery systems to improve the clinical efficacy of these two tetracyclines for their potential application in neurodegenerative diseases. This study reviews the neuroprotective roles of minocycline and doxycycline in four of the main neurodegenerative disorders: AD, PD, ALS and MS. Moreover, the potential applications of nanoparticulate delivery systems developed for both tetracyclines are also reviewed.

Drug delivery based on chitosan, β-cyclodextrin and sodium carboxymethyl cellulose as well as nanocarriers for advanced leukemia treatment

Medicine/nanotechnology as a new and applicable technique according to drug delivery systems has gained great consideration for cancer treatment. Polysaccharides including, cellulose, β-cyclodextrin and sodium carboxymethyl cellulose and chitosan as natural bio-materials, are appropriate candidates for designing and formulations of these nanosystems because of the exceptional advantages such as bio-compatibility, bio-degradability, non-toxicity, and gelling characteristics. An intelligent drug delivery platform based on these hybrids nowadays is developed, which can be used for dual-responsive dual-drug delivery. Nanotechnology accompany with biological molecules has been carefully considered to decrease the drawbacks of conventional cancer treatments. Consequently, this review is intended to state and investigate on the latest development on the combination treatment of platforms based on the hybrids of anticancer drugs/nanoparticles/Polysaccharides in the fields of biomedical therapeutics and cancer therapy owing to the bio-compatibility, great surface area, good chemical and mechanical features, the challenges and future perspectives are reported as well.

Biomaterial and Therapeutic Approaches for the Manipulation of Macrophage Phenotype in Peripheral and Central Nerve Repair

Injury to the peripheral or central nervous systems often results in extensive loss of motor and sensory function that can greatly diminish quality of life. In both cases, macrophage infiltration into the injury site plays an integral role in the host tissue inflammatory response. In particular, the temporally related transition of macrophage phenotype between the M1/M2 inflammatory/repair states is critical for successful tissue repair. In recent years, biomaterial implants have emerged as a novel approach to bridge lesion sites and provide a growth-inductive environment for regenerating axons. This has more recently seen these two areas of research increasingly intersecting in the creation of 'immune-modulatory' biomaterials. These synthetic or naturally derived materials are fabricated to drive macrophages towards a pro-repair phenotype. This review considers the macrophage-mediated inflammatory events that occur following nervous tissue injury and outlines the latest developments in biomaterial-based strategies to influence macrophage phenotype and enhance repair.

Advanced approaches to regenerate spinal cord injury: The development of cell and tissue engineering therapy and combinational treatments

Spinal cord injury (SCI) is a central nervous system (CNS) devastate event that is commonly caused by traumatic or non-traumatic events. The reinnervation of spinal cord axons is hampered through a myriad of devices counting on the damaged myelin, inflammation, glial scar, and defective inhibitory molecules. Unfortunately, an effective treatment to completely repair SCI and improve functional recovery has not been found. In this regard, strategies such as using cells, biomaterials, biomolecules, and drugs have been reported to be effective for SCI recovery. Furthermore, recent advances in combinatorial treatments, which address various aspects of SCI pathophysiology, provide optimistic outcomes for spinal cord regeneration. According to the global importance of SCI, the goal of this article review is to provide an overview of the pathophysiology of SCI, with an emphasis on the latest modes of intervention and current advanced approaches for the treatment of SCI, in conjunction with an assessment of combinatorial approaches in preclinical and clinical trials. So, this article can give scientists and clinicians' clues to help them better understand how to construct preclinical and clinical studies that could lead to a breakthrough in spinal cord regeneration.

Therapeutic targets and nanomaterial-based therapies for mitigation of secondary injury after spinal cord injury

Spinal cord injury (SCI) and the resulting neurological trauma commonly result in complete or incomplete neurological dysfunction and there are few effective treatments for primary SCI. However, the following secondary SCI, including the changes of microvasculature, inflammatory response and oxidative stress around the injury site, may provide promising therapeutic targets. The advances of nanomaterials hold promise for delivering therapeutics to alleviate secondary SCI and promote functional recovery. In this review, we highlight recent achievements of nanomaterial-based therapy, specifically targeting blood-spinal cord barrier disruption, mitigation of the inflammatory response and lightening of oxidative stress after spinal cord injury.

Nanoparticles in traumatic spinal cord injury: therapy and diagnosis

Nanotechnology has been previously employed for constructing drug delivery vehicles, biosensors, solar cells, lubricants and as antimicrobial agents. The advancement in synthesis procedure makes it possible to formulate nanoparticles (NPs) with precise control over physico-chemical and optical properties that are desired for specific clinical or biological applications. The surface modification technology has further added impetus to the specific applications of NPs by providing them with desirable characteristics. Hence, nanotechnology is of paramount importance in numerous biomedical and industrial applications due to their biocompatibility and stability even in harsh environments. Traumatic spinal cord injuries (TSCIs) are one of the major traumatic injuries that are commonly associated with severe consequences to the patient that may reach to the point of paralysis. Several processes occurring at a biochemical level which exacerbate the injury may be targeted using nanotechnology. This review discusses possible nanotechnology-based approaches for the diagnosis and therapy of TSCI, which have a bright future in clinical practice.

The Effect of Inflammatory Priming on the Therapeutic Potential of Mesenchymal Stromal Cells for Spinal Cord Repair

Mesenchymal stromal cells (MSC) are used for cell therapy for spinal cord injury (SCI) because of their ability to support tissue repair by paracrine signaling. Preclinical and clinical research testing MSC transplants for SCI have revealed limited success, which warrants the exploration of strategies to improve their therapeutic efficacy. MSC are sensitive to the microenvironment and their secretome can be altered in vitro by exposure to different culture media. Priming MSC with inflammatory stimuli increases the expression and secretion of reparative molecules. We studied the effect of macrophage-derived inflammation priming on MSC transplants and of primed MSC (pMSC) acute transplants (3 days) on spinal cord repair using an adult rat model of moderate-severe contusive SCI. We found a decrease in long-term survival of pMSC transplants compared with unprimed MSC transplants. With a pMSC transplant, we found significantly more anti-inflammatory macrophages in the contusion at 4 weeks post transplantation (wpt). Blood vessel presence and maturation in the contusion at 1 wpt was similar in rats that received pMSC or untreated MSC. Nervous tissue sparing and functional recovery were similar across groups. Our results indicate that macrophage-derived inflammation priming does not increase the overall therapeutic potential of an MSC transplant in the adult rat contused spinal cord.

Antibiotics with therapeutic effects on spinal cord injury: a review

Accumulating evidence indicates that a considerable number of antibiotics exert anti-inflammatory and neuroprotective effects in different central and peripheral nervous system diseases including spinal cord injury (SCI). Both clinical and preclinical studies on SCI have found therapeutic effects of antibiotics from different families on SCI. These include macrolides, minocycline, β-lactams, and dapsone, all of which have been found to improve SCI sequels and complications. These antibiotics may target similar signaling pathways such as reducing inflammatory microglial activity, promoting autophagy, inhibiting neuronal apoptosis, and modulating the SCI-related mitochondrial dysfunction. In this review paper, we will discuss the mechanisms underlying therapeutic effects of these antibiotics on SCI, which not only could supply vital information for investigators but also guide clinicians to consider administering these antibiotics as part of a multimodal therapeutic approach for management of SCI and its complications.

Promising Role of Nano-Encapsulated Drugs for Spinal Cord Injury

Nanomaterials have been utilized for the drug delivery in the central nervous system (CNS), and many research investigators are currently focussing on this specified area. There has been a lot of advancement in the nanoparticle-mediated drug delivery to the brain. Neuronal injuries including spinal cord injury (SCI) and their targeted therapies are still in its infancy on this planet. SCI has been known to cause axonal damage followed by the loss of communication between CNS and other non-neuronal systems. SCI has been critically associated with prolonged inflammation, sensory dysfunction, and motor impairment in SCI patients. There has been a critical crosstalk in SCI and blood brain barriers (BBBs) for drug absorption and distribution in patients. There is a paucity of possible therapies for proper intervention of SCI due to selective permeability of the drugs across BBB. Nanomaterials are contemplated in the drug delivery system for SCI. In addition, self-assembled nanomicelles, lipid nanoparticles, and other co-polymers have now been explored for neuronal injuries. This review focuses on the promising approach and/or role of nanodrug delivery to target SCI in both in vitro and in vivo models.

Magnesium oil enriched transdermal nanogel of methotrexate for improved arthritic joint mobility, repair, and reduced inflammation

Aim: Methotrexate (Mtx) is prescribed to reduce pain and inflammation in arthritis patients; however, improved repair and mobility of joints still are the major concerns. Magnesium oil (MO) improves joint mobility and repair; therefore, MO-assisted transdermal delivery of Mtx was aimed.Methods: MO integrated Mtx nanoemulsion (Mtx-MONE) was prepared with uniform size (175 ± 35.4 nm), pH (6.15 ± 0.3) near to skin pH, and high entrapment efficiency (65 ± 8.6%). Mtx-MONE was transformed to nanogel (Mtx-MONEG) with semisolid consistency (43,408 ± 77.72 cP) and good spreadability (3.63 ± 0.033 mJ).Results: Mtx-MONEG showed significant reduction in oedema, arthritic scores, level of inflammatory cytokines, and improved walking as compared to diseased control. MO offered additional improvements in joints, mobility, and repair.Conclusion: Transdermal delivery of Mtx has been successfully achieved by Mtx-MONEG. Tremendous recovery from inflammation, improved joints mobility and repair, and reduced pain strongly support the use of MO as an adjutant of Mtx for improved transdermal application.

Local delivery of FTY720 and NSCs on electrospun PLGA scaffolds improves functional recovery after spinal cord injury

Spinal cord injury (SCI) is a common issue in the clinic that causes severe motor and sensory dysfunction below the lesion level. FTY720, also known as fingolimod, has recently been reported to exert a positive effect on the recovery from a spinal cord injury. Through local delivery to the lesion site, FTY720 effectively integrates with biomaterials, and the systemic adverse effects are alleviated. However, the effects of the proper mass ratio of FTY720 in biomaterials on neural stem cell (NSC) proliferation and differentiation, as well as functional recovery after SCI, have not been thoroughly investigated. In our study, we fabricated electrospun poly (lactide-co-glycolide) (PLGA)/FTY720 scaffolds at different mass ratios (0.1%, 1%, and 10%) and characterized these scaffolds. The effects of electrospun PLGA/FTY720 scaffolds on NSC proliferation and differentiation were measured. Then, a rat model of spinal transection was established to investigate the effects of PLGA/FTY720 scaffolds loaded with NSCs. Notably, 1% PLGA/FTY720 scaffolds exerted the best effects on the proliferation and differentiation of NSCs and 10% PLGA/FTY720 was cytotoxic to NSCs. Based on the Basso, Beattie, and Bresnahan (BBB) score, HE staining and immunofluorescence staining, the PLGA/FTY720 scaffold loaded with NSCs effectively promoted the recovery of spinal cord function. Thus, FTY720 properly integrated with electrospun PLGA scaffolds, and electrospun PLGA/FTY720 scaffolds loaded with NSCs may have potential applications for SCI as a nerve implant.

Spinal cord injury (SCI) is a common issue in the clinic that causes severe motor and sensory dysfunction below the lesion level.

Potential immunotherapies for traumatic brain and spinal cord injury

Traumatic injury of the central nervous system (CNS) including brain and spinal cord remains a leading cause of morbidity and disability in the world. Delineating the mechanisms underlying the secondary and persistent injury versus the primary and transient injury has been drawing extensive attention for study during the past few decades. The sterile neuroinflammation during the secondary phase of injury has been frequently identified substrate underlying CNS injury, but as of now, no conclusive studies have determined whether this is a beneficial or detrimental role in the context of repair. Recent pioneering studies have demonstrated the key roles for the innate and adaptive immune responses in regulating sterile neuroinflammation and CNS repair. Some promising immunotherapeutic strategies have been recently developed for the treatment of CNS injury. This review updates the recent progress on elucidating the roles of the innate and adaptive immune responses in the context of CNS injury, the development and characterization of potential immunotherapeutics, as well as outstanding questions in this field.

Biomaterials for revascularization and immunomodulation after spinal cord injury

Spinal cord injury (SCI) causes immediate damage to the nervous tissue accompanied by loss of motor and sensory function. The limited self-repair competence of injured nervous tissue underscores the need for reparative interventions to recover function after SCI. The vasculature of the spinal cord plays a crucial role in SCI and repair. Ruptured and sheared blood vessels in the injury epicenter and blood vessels with a breached blood-spinal cord barrier (BSCB) in the surrounding tissue cause bleeding and inflammation, which contribute to the overall tissue damage. The insufficient formation of new functional vasculature in and near the injury impedes endogenous tissue repair and limits the prospect of repair approaches. Limiting the loss of blood vessels, stabilizing the BSCB, and promoting the formation of new blood vessels are therapeutic targets for spinal cord repair. Inflammation is an integral part of injury-mediated vascular damage, which has deleterious and reparative consequences. Inflammation and the formation of new blood vessels are intricately interwoven. Biomaterials can be effectively used for promoting and guiding blood vessel formation or modulating the inflammatory response after SCI, thereby governing the extent of damage and the success of reparative interventions. This review deals with the vasculature after SCI, the reciprocal interactions between inflammation and blood vessel formation, and the potential of biomaterials to support revascularization and immunomodulation in damaged spinal cord nervous tissue.

Albumin-Conjugated Lipid-Based Multilayered Nanoemulsion Improves Drug Specificity and Anti-Inflammatory Potential at the Spinal Cord Injury gSite after Intravenous Administration

Albumin-conjugated multilayered nanoemulsion (albumin-MNE) of methyl prednisolone (MP) was developed to ensure the specificity of the drug at the spinal cord injury (SCI) site. MNE was prepared by emulsification followed by ionic deposition of oppositely charged polymer followed by albumin conjugation using N-hydroxysuccinimide. Prepared nanoemulsion was characterized for particle size, polydispersity index (PDI), zeta potential (Zp), pH, viscosity, and entrapment efficiency. It was further evaluated for shape and morphological analysis, in vitro release, cell viability, and in vivo efficacy against post SCI-like conditions in terms of behavioral assessment, histopathological evaluation, and immunoflorescence assay of the histological sections showing Bax-driven apoptosis. Entrapment efficiency, particle size, PDI, and Zp of spherical-shaped, smooth-surfaced MNE droplets were found to be 68.9%, 83.2 ± 14.4 nm, 0.231, and + 62.7 mV, respectively. In vitro release of MP from MNE and albumin-MNE was observed to be 68.5 and 72.2% after 96th hour of the study. MNE showed higher viability of astrocytes than MP solution. Albumin-MNE improved behavior of SCI rat and histopathological conditions in a very effective manner when compared with MNE. Immunoflorescence assay reveals explicit decline in mitochondrial-mediated apoptosis by sub-cellular upregulation of Bax at spinal cord injury site. In conclusion, albumin-MNE delivered MP specifically at SCI site and avoided its instant availability inside astrocytes culture. On account of which the chitosan stabilized, lecithin-emulsified, multilayered nanoemulsion of MP depicts higher efficacy and safety than MNE and may offer safe and effective mean for the treatment of post SCI-like conditions in human.

pH-sensitive polymeric nanoparticles with antioxidant and anti-inflammatory properties against cisplatin-induced hearing loss

Polymeric nanoparticles (NPs) based on smart synthetic amphiphilic copolymers are used to transport and controlled release dexamethasone in the inner ear to protect against the ototoxic effect of cisplatin. The NPs were based on a mixture of two pseudo-block polymer drugs obtained by free radical polymerization: poly(VI-co-HEI) and poly(VP-co-MVE) or poly(VP-co-MTOS), being VI 1-vinylimidazole, VP N-vinylpyrrolidone, and HEI, MVE and MTOS the methacrylic derivatives of ibuprofen, α-tocopherol and α-tocopheryl succinate, respectively. The NPs were obtained by nanoprecipitation with appropriate hydrodynamic properties, and isoelectric points that matched the pH of inflamed tissue. The NPs were tested both in vitro (using HEI-OC1 cells) and in vivo (using a murine model) with good results. Although the concentration of dexamethasone administered in the NPs is around two orders of magnitude lower that the conventional treatment for intratympanic administration, the NPs protected from the cytotoxic effect of cisplatin when the combination of the appropriate properties in terms of size, zeta potential, encapsulation efficiency and isoelectric point were achieved. To the best of our knowledge this is the first time that pH sensitive NPs are used to protect from cisplatin-induced hearing loss by intratympanic administration.

Nischarin-siRNA delivered by polyethylenimine-alginate nanoparticles accelerates motor function recovery after spinal cord injury

A previous study by our group found that inhibition of nischarin promotes neurite outgrowth and neuronal regeneration in Neuro-2a cells and primary cortical neurons. In recent years, more and more studies have shown that nanomaterials have good prospects in treatment of spinal cord injury. We proposed that small interfering RNA targeting nischarin (Nis-siRNA) delivered by polyethyleneimine-alginate (PEI-ALG) nanoparticles promoted motor function recovery in rats with spinal cord injury. Direct microinjection of 5 μL PEI-ALG/Nis-siRNA into the spinal cord lesion area of spinal cord injury rats was performed. From day 7 after surgery, Basso, Beattie and Bresnahan score was significantly higher in rats from the PEI-ALG/Nis-siRNA group compared with the spinal cord injury group and PEI-ALG/Control-siRNA group. On day 21 after injection, hematoxylin-eosin staining showed that the necrotic area was reduced in the PEI-ALG/Nis-siRNA group. Immunohistochemistry and western blot assay results confirmed successful inhibition of nischarin expression and increased protein expression of growth-associated protein-43 in the PEI-ALG/Nis-siRNA group. These findings suggest that a complex of PEI-ALG nanoparticles and Nis-siRNA effectively suppresses nischarin expression, induces expression of growth-associated protein-43, and accelerates motor function recovery after spinal cord injury.