Perspective Insights to Bio-Nanomaterials for the Treatment of Neurological Disorders

In vitro 3D skin culture and its sustainability in toxicology: a narrative review

In current toxicological research, 2D cell cultures and animal models are well- accepted and commonly employed methods. However, these approaches have many drawbacks and are distant from the actual environment in human. To embrace this, great efforts have been made to provide alternative methods for non-animal skin models in toxicology studies with the need for more mechanistically informative methods. This review focuses on the current state of knowledge regarding the in vitro 3D skin model methods, with different functional states that correspond to the sustainability in the field of toxicology testing. We discuss existing toxicology testing methods using in vitro 3D skin models which provide a better understanding of the testing requirements that are needed. The challenges and future landscape in using the in vitro 3D skin models in toxicology testing are also discussed. We are confident that the in vitro 3D skin models application may become an important tool in toxicology in the context of risk assessment.

Biomaterials in Traumatic Brain Injury: Perspectives and Challenges

Traumatic brain injury (TBI) is a leading cause of mortality and long-term impairment globally. TBI has a dynamic pathology, encompassing a variety of metabolic and molecular events that occur in two phases: primary and secondary. A forceful external blow to the brain initiates the primary phase, followed by a secondary phase that involves the release of calcium ions (Ca2+) and the initiation of a cascade of inflammatory processes, including mitochondrial dysfunction, a rise in oxidative stress, activation of glial cells, and damage to the blood-brain barrier (BBB), resulting in paracellular leakage. Currently, there are no FDA-approved drugs for TBI, but existing approaches rely on delivering micro- and macromolecular treatments, which are constrained by the BBB, poor retention, off-target toxicity, and the complex pathology of TBI. Therefore, there is a demand for innovative and alternative therapeutics with effective delivery tactics for the diagnosis and treatment of TBI. Tissue engineering, which includes the use of biomaterials, is one such alternative approach. Biomaterials, such as hydrogels, including self-assembling peptides and electrospun nanofibers, can be used alone or in combination with neuronal stem cells to induce neurite outgrowth, the differentiation of human neural stem cells, and nerve gap bridging in TBI. This review examines the inclusion of biomaterials as potential treatments for TBI, including their types, synthesis, and mechanisms of action. This review also discusses the challenges faced by the use of biomaterials in TBI, including the development of biodegradable, biocompatible, and mechanically flexible biomaterials and, if combined with stem cells, the survival rate of the transplanted stem cells. A better understanding of the mechanisms and drawbacks of these novel therapeutic approaches will help to guide the design of future TBI therapies.

Current Advances in Stimuli-Responsive Hydrogels as Smart Drug Delivery Carriers

In recent years, significant advancements in the field of advanced materials and hydrogel engineering have enabled the design and fabrication of smart hydrogels and nanogels that exhibit sensitivity to specific signals or pathological conditions, leading to a wide range of applications in drug delivery and disease treatment. This comprehensive review aims to provide an in-depth analysis of the stimuli-responsive principles exhibited by smart hydrogels in response to various triggers, such as pH levels, temperature fluctuations, light exposure, redox conditions, or the presence of specific biomolecules. The functionality and performance characteristics of these hydrogels are highly influenced by both their constituent components and fabrication processes. Key design principles, their applications in disease treatments, challenges, and future prospects were also discussed. Overall, this review aims to contribute to the current understanding of gel-based drug delivery systems and stimulate further research in this rapidly evolving field.

Injectable Hydrogel Guides Neurons Growth with Specific Directionality

Visual disabilities affect more than 250 million people, with 43 million suffering from irreversible blindness. The eyes are an extension of the central nervous system which cannot regenerate. Neural tissue engineering is a potential method to cure the disease. Injectability is a desirable property for tissue engineering scaffolds which can eliminate some surgical procedures and reduce possible complications and health risks. We report the development of the anisotropic structured hydrogel scaffold created by a co-injection of cellulose nanofiber (CNF) solution and co-polypeptide solution. The positively charged poly (L-lysine)-r-poly(L-glutamic acid) with 20 mol% of glutamic acid (PLLGA) is crosslinked with negatively charged CNF while promoting cellular activity from the acid nerve stimulate. We found that CNF easily aligns under shear forces from injection and is able to form hydrogel with an ordered structure. Hydrogel is mechanically strong and able to support, guide, and stimulate neurite growth. The anisotropy of our hydrogel was quantitatively determined in situ by 2D optical microscopy and 3D X-ray tomography. The effects of PLLGA:CNF blend ratios on cell viability, neurite growth, and neuronal signaling are systematically investigated in this study. We determined the optimal blend composition for stimulating directional neurite growth yielded a 16% increase in length compared with control, reaching anisotropy of 30.30% at 10°/57.58% at 30°. Using measurements of calcium signaling in vitro, we found a 2.45-fold increase vs. control. Based on our results, we conclude this novel material and unique injection method has a high potential for application in neural tissue engineering.

A systematic study of nano-based fibrous systems: Diagnostic and therapeutic approaches for dementia control

Nano-based systems provide many advantages, including eluding gastrointestinal and first-pass metabolism of the drug and improving the potential advantage of reduced doses of drugs for an equal or better therapeutic effect compared to other parts of oral administration. Over the last few years, protein-based nanofibrous biomaterials have been used for better controlling dementia. PubMed, Scopus, and ISI Web of Science were consulted for available articles on nano-based fibrous systems for the treatment and diagnosis of dementia (up to October 2022). Of 725 articles that were identified and evaluated, only 19 were included. Eleven studies evaluated nanofibrous electrospun biomaterials for better dementia control. Among these, four investigated marker/biomarker detection for the early diagnosis of dementia. Two from four studies conducted hydrogel-based nanofibrous for Alzheimer's disease (AD) treatment. Additionally, four studies inspected stem cell (SC) transplantation on nano-based fibrous scaffolds for better treatment of dementia. Finally, two from the final four studies considered nano-based fibrous systems for the enhanced treatment of dementia. Our study concluded that nano-based fibrous platforms, exclusively peptide/protein-based nanofibrous scaffolds made from biomaterials, can be applied for dementia management by either diagnostic or therapeutic approaches specific in purpose-designed electrospun nanofibrous scaffolds.

Nanodelivery of Dietary Polyphenols for Therapeutic Applications

Advancement in nanotechnology has unleashed the therapeutic potentials of dietary polyphenols by enhancing bioavailability, improving biological half-life, and allowing site-specific drug delivery. In this review, through citation of relevant literature reports, we discuss the application of nano-pharmaceutical formulations, such as solid lipid nanoparticles, nano-emulsions, nano-crystals, nano-polymersomes, liposomes, ethosomes, phytosomes, and invasomes for dietary polyphenols. Following this, we highlight important studies concerning different combinations of nano formulations with dietary polyphenols (also known as nanophytopolyphenols). We also provide nano-formulation paradigms for enhancing the physicochemical properties of dietary polyphenols. Finally, we highlight the latest patents that were granted on nano-formulations of dietary polyphenols. Based on our review, we observe that nanosized delivery of herbal constituents, spices, and dietary supplements have the ability to improve biological processes and address issues connected with herbal treatments.

Silk-Elastin-like Polymers for Acute Intraparenchymal Treatment of the Traumatically Injured Spinal Cord: A First Systematic Experimental Approach

Despite the promising potential of hydrogel-based therapeutic approaches for spinal cord injury (SCI), the need for new biomaterials to design effective strategies for SCI treatment and the outstanding properties of silk-elastin-like polymers (SELP), the potential use of SELPs in SCI is currently unknown. In this context, we assessed the effects elicited by the in vivo acute intraparenchymal injection of an SELP named (EIS)₂-RGD6 in a clinically relevant model of SCI. After optimization of the injection system, the distribution, structure, biodegradability, and cell infiltration capacity of (EIS)₂-RGD6 were assessed. Finally, the effects exerted by the (EIS)₂-RGD6 injection-in terms of motor function, myelin preservation, astroglial and microglia/macrophage reactivity, and fibrosis-were evaluated. We found that (EIS)₂-RGD6 can be acutely injected in the lesioned spinal cord without inducing further damage, showing a widespread distribution covering all lesioned areas with a single injection and facilitating the formation of a slow-degrading porous scaffold at the lesion site that allows for the infiltration and/or proliferation of endogenous cells with no signs of collapse and without inducing further microglial and astroglial reactivity, as well as even reducing SCI-associated fibrosis. Altogether, these observations suggest that (EIS)₂-RGD6-and, by extension, SELPs-could be promising polymers for the design of therapeutic strategies for SCI treatment.

The Encapsulation of Citicoline within Solid Lipid Nanoparticles Enhances Its Capability to Counteract the 6-Hydroxydopamine-Induced Cytotoxicity in Human Neuroblastoma SH-SY5Y Cells

(1) Backgrond: Considering the positive effects of citicoline (CIT) in the management of some neurodegenerative diseases, the aim of this work was to develop CIT-Loaded Solid Lipid Nanoparticles (CIT-SLNs) for enhancing the therapeutic use of CIT in parkinsonian syndrome; (2) Methods: CIT-SLNs were prepared by the melt homogenization method using the self-emulsifying lipid Gelucire® 50/13 as lipid matrix. Solid-state features on CIT-SLNs were obtained with FT-IR, thermal analysis (DSC) and X-ray powder diffraction (XRPD) studies. (3) Results: CIT-SLNs showed a mean diameter of 201 nm, −2.20 mV as zeta potential and a high percentage of entrapped CIT. DSC and XRPD analyses evidenced a greater amorphous state of CIT in CIT-SLNs. On confocal microscopy, fluorescent SLNs replacing unlabeled CIT-SLNs released the dye selectively in the cytoplasm. Biological evaluation showed that pre-treatment of SH-SY5Y dopaminergic cells with CIT-SLNs (50 µM) before the addition of 40 µM 6-hydroxydopamine (6-OHDA) to mimic Parkinson’s disease’s degenerative pathways counteracts the cytotoxic effects induced by the neurotoxin, increasing cell viability with the consistent maintenance of both nuclear and cell morphology. In contrast, pre-treatment with CIT 50 and 60 µM or plain SLNs for 2 h followed by 6-OHDA (40 µM) did not significantly influence cell viability. (4) Conclusions: These data suggest an enhanced protection exerted by CIT-SLNs with respect to free CIT and prompt further investigation of possible molecular mechanisms that underlie this difference.

Biofabrication of Silver Nanoparticles (AgNPs) Using Embelin for Effective Therapeutic Management of Lung Cancer

Nanobiotechnology is a burgeoning field of research with applications in cancer treatment, targeted chemotherapy, and molecular diagnosis. This study aims at the fabrication of silver nanoparticles using embelin derived from Embelia ribes to evaluate its anticancer property. Silver nanoparticles (AgNPs) have emerged as a novel nano-carrier for therapeutic agents with a wide range of medical capabilities due to their unique structural, physicochemical, and optical features. In our study, the particle size of fabricated AgNPs was measured as 25 nm, and the zeta potential was recorded as -5.42 mV, which indicates the good stability of embelin-derived AgNPs. The crystalline surface morphology was observed by SEM analysis. The FT-IR spectrum confirmed the reduction in silver ions (Ag+) by embelin, and the TEM analysis exhibited polydispersed Ag+ of 20-30 nm. The anticancer potential of embelin-fabricated AgNPs was investigated using in vitro studies on lung cancer cells by the MTT assay. The results revealed significant dose-dependent inhibition of cell proliferation against A549 cell lines. Embelin AgNP-induced apoptosis was measured by the annexin-V PI apoptosis assay, which exhibited significantly low necrotic cells as compared to apoptotic cells. Finally, the findings of our study suggest the anticancer potential of biofabricated embelin AgNPs, particularly against lung cancer cells.

Lignin-Based Porous Biomaterials for Medical and Pharmaceutical Applications

Over the past decade, lignin-based porous biomaterials have been found to have strong potential applications in the areas of drug delivery, tissue engineering, wound dressing, pharmaceutical excipients, biosensors, and medical devices. Lignin-based porous biomaterials have the addition of lignin obtained from lignocellulosic biomass. Lignin as an aromatic compound is likely to modify the materials’ mechanical properties, thermal properties, antioxidant, antibacterial property, biodegradability, and biocompatibility. The size, shape, and distribution of pores can determine the materials’ porous structure, porosity, surface areas, permeability, porosity, water solubility, and adsorption ability. These features could be suitable for medical applications, especially controlled drug delivery systems, wound dressing, and tissue engineering. In this review, we provide an overview of the current status and future potential of lignin-based porous materials for medical and pharmaceutical uses, focusing on material types, key properties, approaches and techniques of modification and fabrication, and promising medical applications.

Novel Nanoparticles Based on N,O-Carboxymethyl Chitosan-Dopamine Amide Conjugate for Nose-to-Brain Delivery

A widely investigated approach to bypass the blood brain barrier is represented by the intranasal delivery of therapeutic agents exploiting the olfactory or trigeminal connections nose-brain. As for Parkinson’s disease (PD), characterized by dopaminergic midbrain neurons degeneration, currently there is no disease modifying therapy. Although several bio-nanomaterials have been evaluated for encapsulation of neurotransmitter dopamine (DA) or dopaminergic drugs in order to restore the DA content in parkinsonian patients, the premature leakage of the therapeutic agent limits this approach. To tackle this drawback, we undertook a study where the active was linked to the polymeric backbone by a covalent bond. Thus, novel nanoparticles (NPs) based on N,O-Carboxymethylchitosan-DA amide conjugate (N,O-CMCS-DA) were prepared by the nanoprecipitation method and characterized from a technological view point, cytotoxicity and uptake by Olfactory Ensheating Cells (OECs). Thermogravimetric analysis showed high chemical stability of N,O-CMCS-DA NPs and X-ray photoelectron spectroscopy evidenced the presence of amide linkages on the NPs surface. MTT test indicated their cytocompatibility with OECs, while cytofluorimetry and fluorescent microscopy revealed the internalization of labelled N,O-CMCS-DA NPs by OECs, that was increased by the presence of mucin. Altogether, these findings seem promising for further development of N,O-CMCS-DA NPs for nose-to-brain delivery application in PD.

Human mini brains and spinal cords in a dish: Modeling strategies, current challenges, and prospective advances

Engineered three-dimensional (3D) in vitro and ex vivo neural tissues, also known as "mini brains and spinal cords in a dish," can be derived from different types of human stem cells via several differentiation protocols. In general, human mini brains are micro-scale physiological systems consisting of mixed populations of neural progenitor cells, glial cells, and neurons that may represent key features of human brain anatomy and function. To date, these specialized 3D tissue structures can be characterized into spheroids, organoids, assembloids, organ-on-a-chip and their various combinations based on generation procedures and cellular components. These 3D CNS models incorporate complex cell-cell interactions and play an essential role in bridging the gap between two-dimensional human neuroglial cultures and animal models. Indeed, they provide an innovative platform for disease modeling and therapeutic cell replacement, especially shedding light on the potential to realize personalized medicine for neurological disorders when combined with the revolutionary human induced pluripotent stem cell technology. In this review, we highlight human 3D CNS models developed from a variety of experimental strategies, emphasize their advances and remaining challenges, evaluate their state-of-the-art applications in recapitulating crucial phenotypic aspects of many CNS diseases, and discuss the role of contemporary technologies in the prospective improvement of their composition, consistency, complexity, and maturation.