Brain-targeted drug delivery assisted by physical techniques and its potential applications in traditional Chinese medicine

Self-Assembled systems for Nose-to-Brain delivery of Temozolamide (TMZ) in brain tumor therapy

Glioblastoma multiforme (GBM) is an aggressive and highly invasive primary brain tumor with poor prognosis and resistance to conventional therapies. The therapeutic efficacy of existing treatments is significantly hampered by the presence of the blood-brain barrier (BBB), tumor heterogeneity, and intrinsic drug resistance mechanisms. Temozolomide (TMZ), the standard chemotherapeutic agent for GBM, suffers from low bioavailability, rapid systemic clearance, and enzymatic degradation, limiting its clinical success. This review highlights the potential of self-assembled nanocarrier-based drug delivery systems for enhancing the therapeutic index of TMZ through intranasal administration, which provides a direct and non-invasive route to the brain, circumventing the BBB and improving central nervous system (CNS) drug bioavailability. Self-assembled systems are highly customizable, allowing for precise control over particle size, surface charge, and release profiles, which can be tailored to improve the penetration and retention of TMZ in the brain. We comprehensively discuss recent advancements in polymeric nanoparticles, liposomes, micelles, niosomes, and solid lipid nanoparticles, emphasizing their physicochemical properties, pharmacokinetics, and mechanisms of targeted drug release. Additionally, we explore molecular and oxidative stress-related pathways contributing to GBM progression and TMZ resistance. Emerging research suggests that nanocarrier-based intranasal delivery of TMZ enhances drug stability, prolongs brain retention time, and minimizes systemic toxicity, offering a promising avenue for improving GBM treatment outcomes.

Plant-derived exosomes in therapeutic nanomedicine, paving the path toward precision medicine

BACKGROUND

Plant-derived exosomes (PDEs), are nanoscale vesicles secreted by multivesicular bodies, play pivotal roles in critical biological processes, including gene regulation, cell communication, and immune defense against pathogens. Recognized for their potential health-promoting properties, PDEs are emerging as innovative components in functional nutrition, poised to enhance dietary health benefits.

PURPOSE

To describe the efficacy of PDEs in nanoform and their application as precision therapy in many disorders.

STUDY DESIGN

The design of this review was carried out in PICO format using randomized clinical trials and research articles based on in vivo and in vitro studies.

METHODS

All the relevant clinical and research studies conducted on plant-derived nanovesicle application and efficacy were included, as retrieved from PubMed and Cochrane, after using specific search terms. This review was performed to determine PDEs' efficacy as nanomedicine and precision therapy. Sub-group analysis and primary data were included to determine the relationship with PDEs.

RESULT

PDEs are extracted from plant materials using sophisticated techniques like precipitation, size exclusion, immunoaffinity capture, and ultracentrifugation, encapsulating vital molecules such as lipids, proteins, and predominantly microRNAs. Although their nutritional impact may be minimal in small quantities, the broader application of PDEs in biomedicine, particularly as vehicles for drug delivery, underscores their significance. They offer a promising strategy to improve the bioavailability and efficacy of therapeutic agents carrying nano-bioactive substances that exhibit anti-inflammatory, antioxidant, cardioprotective, and anti-cancer activities.

CONCLUSION

PDEs enhance the therapeutic potency of plant-derived phytochemicals, supporting their use in disease prevention and therapy. This comprehensive review explores the multifaceted aspects of PDEs, including their isolation methods, biochemical composition, health implications, and potential to advance medical and nutritional interventions.

Diabetes mellitus and Alzheimer's disease: Understanding disease mechanisms, their correlation, and promising dual activity of selected herbs

ETHNOPHARMACOLOGICAL RELEVANCE

This review explores the link between Type 2 Diabetes Mellitus (T2DM) and diabetes-induced Alzheimer's disease (AD). It emphasizes the shared pathophysiological links and mechanisms between the two conditions, focusing on reduced insulin levels and receptors, impaired glucose metabolism, insulin resistance, mitochondrial dysfunction, and oxidative damage in AD-affected brains-paralleling aspects of T2DM. The review suggests AD as a "diabetes of the brain," supported by cognitive enhancement through antidiabetic interventions. It focuses on the traditionally used Indian herbs as a means to manage both conditions while addressing developmental challenges.

AIM OF THE STUDY

This study explores the DM-AD connection, reviewing medicinal herbs with protective potential for both ailments, considering traditional uses and developmental challenges.

MATERIALS AND METHODS

Studied research, reviews, and ethnobotanical and scientific data from electronic databases and traditional books.

RESULTS

The study analyzes the pathophysiological links between DM and AD, emphasizing their interconnected factors. Eight Ayurvedic plants with dual protective effects against T2DM and AD are thoroughly reviewed with preclinical/clinical evidence. Historical context, phytoconstituents, and traditional applications are explored. Innovative formulations using these plants are examined. Challenges stemming from phytoconstituents' physicochemical properties are highlighted, prompting novel formulation development, including nanotechnology-based delivery systems. The study uncovers obstacles in formulating treatments for these diseases.

CONCLUSION

The review showcases the dual potential of chosen medicinal herbs against both diseases, along with their traditional applications, endorsing their use. It addresses formulation obstacles, proposing innovative delivery technologies for herbal therapies, while acknowledging their constraints. The review suggests the need for heightened investment and research in this area.

Development of Telmisartan Nanocrystal-Based Dissolving Microneedle for Brain Targeting via Trigeminal Pathway: A Potentially Promising Treatment for Alzheimer's with an Improved Pharmacokinetic Profile

Telmisartan (TMN), an angiotensin receptor blocker (ARB) drug, is being considered as an alternative therapy for Alzheimer's disease (ALZ). However, when taken orally, its low water solubility leads to a low bioavailability and brain concentration. To overcome this problem, TMN was formulated as nanocrystals (NC), then incorporated into dissolving microneedles (DMN) to enhance drug delivery to the brain via the trigeminal route on the face. TMN-NC was formulated with 1% PVA using the top-down method and stirred for 12 h, producing the smallest particle size of 132 ± 11 nm and showing a better release profile, reaching 89.51 ± 7.52% (2 times greater than pure TMN). TMN-NC-DMN with a combination of 15% PVA and 25% PVP showed optimal mechanical strength and penetration ability; they could dissolve completely within 15 min, and their surface pH was safe for the skin. The permeation test of TMN-NC-DMN showed the highest concentration, reaching 285.80 ± 32.12 μg/mL, compared to TMN-DMN and patch control, which only reached 87.17 ± 11.24 and 94.00 ± 11.09 μg/mL, respectively. The TMN-NC-DMN combination showed better bioavailability and was found to be well-delivered to the brain without any irritation to the skin. Pharmacokinetic parameters had a significant difference (p > 0.05) compared to other preparations, making it a promising treatment for ALZ.

Long-Acting Therapeutic Delivery Systems for the Treatment of Gliomas

Despite the emergence of cutting-edge therapeutic strategies and tremendous progress in research, a complete cure of glioma remains elusive. The heterogenous nature of tumor, immunosuppressive state and presence of blood brain barrier are few of the major obstacles in this regard. Long-acting depot formulations such as injectables and implantables are gaining attention for drug delivery to brain owing to their ease in administration and ability to elute drug locally for extended durations in a controlled manner with minimal toxicity. Hybrid matrices fabricated by incorporating nanoparticulates within such systems help to enhance pharmaceutical advantages. Utilization of long-acting depots as monotherapy or in conjunction with existing strategies rendered significant survival benefits in many preclinical studies and some clinical trials. The discovery of novel targets, immunotherapeutic strategies and alternative drug administration routes are now coupled with several long-acting systems with an ultimate aim to enhance patient survival and prevent glioma recurrences.

New Drug Delivery Systems Developed for Brain Targeting

The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (B_CSF) are two of the most complex and sophisticated concierges that defend the central nervous system (CNS) by numerous mechanisms. While they maintain the neuro-ecological homeostasis through the regulated entry of essential biomolecules, their conservative nature challenges the entry of most of the drugs intended for CNS delivery. Targeted delivery challenges for a diverse spectrum of therapeutic agents/drugs (non-small molecules, small molecules, gene-based therapeutics, protein and peptides, antibodies) are diverse and demand specialized delivery and disease-targeting strategies. This review aims to capture the trends that have shaped the current brain targeting research scenario. This review discusses the physiological, neuropharmacological, and etiological factors that participate in the transportation of various drug delivery cargoes across the BBB/B_CSF and influence their therapeutic intracranial concentrations. Recent research works spanning various invasive, minimally invasive, and non-invasive brain- targeting approaches are discussed. While the pre-clinical outcomes from many of these approaches seem promising, further research is warranted to overcome the translational glitches that prevent their clinical use. Non-invasive approaches like intranasal administration, P-glycoprotein (P-gp) inhibition, pro-drugs, and carrier/targeted nanocarrier-aided delivery systems (alone or often in combination) hold positive clinical prospects for brain targeting if explored further in the right direction.