Review of Pharmacotherapeutic Targets in Alzheimer's Disease and Its Management Using Traditional Medicinal Plants.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory loss, and impaired daily functioning. While there is currently no cure for AD, several pharmacotherapeutic targets and management strategies have been explored. Additionally, traditional medicinal plants have gained attention for their potential role in AD management. Pharmacotherapeutic targets in AD include amyloid-beta (Aß) aggregation, tau protein hyperphosphorylation, neuroinflammation, oxidative stress, and cholinergic dysfunction. Traditional medicinal plants, such as Ginkgo biloba, Huperzia serrata, Curcuma longa (turmeric), and Panax ginseng, have demonstrated the ability to modulate these targets through their bioactive compounds. Ginkgo biloba, for instance, contains flavonoids and terpenoids that exhibit neuroprotective effects by reducing Aß deposition and enhancing cerebral blood flow. Huperzia serrata, a natural source of huperzine A, has acetylcholinesterase-inhibiting properties, thus improving cholinergic function. Curcuma longa, enriched with curcumin, exhibits anti-inflammatory and antioxidant effects, potentially mitigating neuroinflammation and oxidative stress. Panax ginseng's ginsenosides have shown neuroprotective and anti-amyloidogenic properties. The investigation of traditional medicinal plants as a complementary approach to AD management offers several advantages, including a lower risk of adverse effects and potential multi-target interactions. Furthermore, the cultural knowledge and utilization of these plants provide a rich source of information for the development of new therapies. However, further research is necessary to elucidate the precise mechanisms of action, standardize preparations, and assess the safety and efficacy of these natural remedies. Integrating traditional medicinal-plant-based therapies with modern pharmacotherapies may hold the key to a more comprehensive and effective approach to AD treatment. This review aims to explore the pharmacotherapeutic targets in AD and assess the potential of traditional medicinal plants in its management.

Physical characterization and bioavailability assessment of 5-fluorouracil-based nanostructured lipid carrier (NLC): In vitro drug release, Hemolysis, and permeability modulation.

5-Fluorouracil (5-FU) is an anticancer agent belonging to BCS Class III that exhibits poor release characteristics and low retention in the biological system. The main objective of this investigation was to develop a drug delivery system, i.e., Nanostructure Lipid Carriers (NLCs) loaded with 5-FU to prolong its biological retention through 5-FU-loaded NLCs (5-FUNLC) were designed to manipulate physicochemical characteristics and assessment of in vitro and in vivo performance. The developed NLCs underwent comprehensive characterization, including assessments for particle size, zeta potential, morphological evaluation, and FT-IR spectroscopy. Additionally, specific evaluations were conducted for 5-FUNLCs, encompassing analyses for encapsulation efficiency of the drug, release characteristics in PBS at pH 6.8, and stability study. The lipophilic character of 5-FUNLC was confirmed through the measurement of the partition coefficient (log P). 5-FUNLCs were observed as spherical-shaped particles with a mean size of 300 ± 25 nm. The encapsulation efficiency was determined to be 89%, indicating effective drug loading within the NLCs. Furthermore, these NLCs exhibited a sustained release nature lasting up to 3-4 h, indicating their potential for controlled drug release over time. Lipid components were biocompatible with the 5-FU to determine thermal transition temperature and show good stability for 30 days. Additionally, an in vitro hemolysis study that confirmed the system did not cause any destruction to the RBCs during intravenous administration. The drug's gut permeability was assessed utilizing the optimized 5-FUNLC (F2) in comparison to 5-FU through the intestine or gut sac model (in the apical to basolateral direction, A → B). The permeability coefficient was measured as 4.91 × 10-5 cm/h with a significant difference. Additionally, the antioxidant potential of the NLCs was demonstrated through the DPPH method. The NLCs' performance was further assessed through in vivo pharmacokinetic studies on Wistar Rats, resulting in a 1.5-fold enhancement in their activity compared to free 5-FU. These NLCs offer improved drug solubility and sustained release, which collectively contribute to enhanced therapeutic outcomes and modulate bioavailability. The study concludes by highlighting the potential of 5-FUNLC as an innovative and efficient drug delivery system. The findings suggest that further preclinical investigations are warranted, indicating a promising avenue for the development of more effective and well-tolerated treatments for cancer.

Comparative analysis of PEG-liposomes and RBCs-derived nanovesicles for anti-tumor therapy.

Lipid-based vesicular nanoparticles, for instance liposomes, conjugated with polyethylene glycol (PEG) have proven to be the closest to an ideal drug delivery vehicle, making way for several PEG-liposomes based nanomedicines in market. However, the synthetic nature of the nanomaterial poses a threat to stimulate immune system. Alternatively, nanovesicles derived from mammalian cells, such as RBCs, have gained interests as they may not elicit much immune response due to the presence of host specific self-recognition markers on their surface. While several reports demonstrating the superior efficacy of these naturally derived vesicles have come out in the last few years, a comparison with clinically established liposomes is still missing. Thus, we conducted an in-vitro and in-vivo comparative studies between PEG-Liposomes and nanovesicles (NVEs) derived from red blood cell (RBC) membrane with an aim to establish a biocompatible nanocarrier for efficient delivery of chemotherapeutic drugs and photothermal agents.

Red blood cells membrane-derived nanoparticles: Applications and key challenges in their clinical translation.

Cellular membrane-derived nanoparticles, particularly of red blood cells (RBCs), represent an emerging class of drug delivery systems. The lack of nucleus and organelles in these cells makes them easy to process and empty out intracellular contents. The empty vesicle membranes can then be either used as a coating on nanoparticles or can be reassembled into a nanovesicle. Engineered RBCs membrane has unique ability to retain its lipid bilayer architecture with host's proteins during top-down approach, thus allowing it to form stable nanoformulations mimicking RBCs stealth properties. In addition, its core-shell structure allows loading of different drug molecules, and its surface chemistry can be manipulated by facile conjugation with ligands on the shell. The remarkable ability of RBCs membrane to fuse with membranes of other cells enables the formation of hybrid nanovesicles. In this review, we highlight the biomedical applications of such vesicles and discuss the potential challenges related to its clinical translation. Although nano-RBCs retain much of the host's proteins, which may give an edge over synthetic nanoparticles in terms of lower immunogenicity, its production at industrial level is more challenging. This review gives the critical analysis of barriers involved in the translation of RBCs-derived nanoparticles from preclinical to clinical level. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.

Engineering Cellular Membrane for Dual Mode Therapy Using NIR Responsive Photosensitizer and Reversible Topoisomerase Inhibition Activity.

Extensive research over past few decades has highlighted the challenges of chemotherapy and prompted the need for multimodality therapy because chemotherapy alone cannot fully eradicate the tumor due to physiological barriers in its effective delivery and systemic side effects. It can be mitigated by adopting nanoparticles as more effective delivery method, but none of them completely prevents drug toxicities. Utilizing multiple therapeutic modes such as phototherapy that can act synergistically with chemotherapy in controlling tumor growth, while reducing the overall dosage, could become a preferred route for cancer management. Careful selection of nanoparticle system, which can simultaneously deliver both drug and photosensitizer, can significantly enhance the therapeutic outcome. Therefore, in this paper, we report development and potential of immune-compatible and long circulating nanoerythrosomes for enhancing the therapeutic potential of camptothecin and indocyanine green against murine cancer model. The RBCs membrane simultaneously loaded the nonpolar drug and amphiphilic photosensitizer in its lipid bilayer, which self-assembled to form stable nanoparticles. These nano constructs absorbed light in the near-infrared region and hence are suitable for targeting deep seated tissues. The dual chemo-phototherapy had great effect on cell viability and had therapeutic value.

Polymeric micelles coated with hybrid nanovesicles enhance the therapeutic potential of the reversible topoisomerase inhibitor camptothecin in a mouse model.

Nanoparticles with longer blood circulation, high loading capacity, controlled release at the targeted site, and preservation of camptothecin (CPT) in its lactone form are the key characteristics for the effective delivery of CPT. In this regard, natural membrane-derived nanovesicles, particularly those derived from RBC membrane, are important. RBC membrane can be engineered to form vesicles or can be coated over synthetic nanoparticles, without losing their basic structural features and can have prolonged circulation time. Here, we developed a hybrid system to encapsulate CPT inside the amphiphilic micelle and coat it with RBC membrane. Thus, it uses the dual ability of polymeric micelles to preserve CPT in its active form, while maintaining its "stealth" effect due to conserved RBC membrane coating. The hybrid system stabilized 60% of the drug in its active form even after 30 h of incubation in serum, in contrast to 15% active form present in free drug formulation after 1 h of incubation. It showed strong retention inside the Ehrlich Ascites Carcinoma (EAC) mice models for at least 72 h, suggesting camouflaging ability conferred by RBC membrane. Additionally, the nano formulation retarded the tumor growth rate more efficiently than free drug, with no evident signs of necrotic skin lesions. Histopathological analysis showed a significant reduction in cardiac atrophy, hepato-renal degeneration, and lung metastasis, which resulted in the increased overall survival of mice treated with the nano formulation. Hence, CPT-loaded polymeric micelles when coated with RBC membrane can prove to be a better system for the delivery of poorly soluble drug camptothecin.

Modulating neutrophil extracellular traps for wound healing.

A diabetic microenvironment primes neutrophils for NETosis, a process of formation of neutrophil extracellular traps (NETs) that further degrades the neutrophils and makes them unavailable for the early-stage inflammatory processes. Mechanistically, simple modification of arginine residues of histones to citrulline by peptidylarginine deiminase (PAD4) enzyme is considered to be a prerequisite for NETosis. In fact, under diabetic conditions, an increase in PAD4-mediated NET formation is considered as one of the reasons for impaired wound healing. Therefore, in the present work, an alginate-GelMa (generally recognized as safe category by FDA, USA) based hydrogel scaffold containing a tripeptide (Thr-Asp-F-amidine) that inhibits PAD4 is developed, based on the hypothesis that inhibiting PAD4 enzyme might offer a way to enhance wound healing under diabetic conditions. The scaffolds are thoroughly characterized for their physicochemical and biological properties. Furthermore, neutrophil-scaffold interactions in terms of NETosis ability and release of other related biomarkers are studied. The wound healing ability is evaluated by a cell migration assay. In vivo wound healing efficacy of the developed scaffolds is demonstrated using a diabetic rat model. The results suggest a reduction in NETosis in the presence of a PAD4 inhibitor. Thus, the study demonstrates a novel scaffold system to deliver the PAD4 inhibitor that can be used to modulate NETosis and improve wound healing.

Red Blood Cells-Derived Vesicles for Delivery of Lipophilic Drug Camptothecin.

Recently, cell membrane-derived nanoparticles, particularly of RBCs, have been explored for delivery of hydrophilic solutes of varied size and complexities. So far, these naturally derived nanoparticles show a significant overlap with liposomes in terms of stability, solute encapsulation, and release. Unlike hydrophilic molecules, which are loaded inside the aqueous core, hydrophobic moieties largely partition inside the lipophilic shell, hence fate of these nanocarriers may be different. Since vesicles have more complex membrane architecture (due to natural lipids and additional proteins and glycoproteins), ease of loading hydrophobic drug, its release pattern, and overall particle stability cannot be compared to those of synthetic lipid-based carriers. Therefore, we derived nanovesicles (NVEs) from RBC membrane, loaded with hydrophobic drug camptothecin (CPT) and labeled noncovalently with amphiphilic fluorophore (CM-DiI). Although both CPT and CM-DiI are known to partition inside the membrane, the overall stability of NVEs and composition of membrane proteins, particularly CD47, "marker of self", did not change. Additionally, the developed NVEs were found to be nonphagocytic even in the presence of serum and showed minimal stimulation of macrophages to release cytokines. Further, this system showed slow release but strong retention of CPT and CM-DiI, respectively, over 24 h, hence appropriate for theranostic applications. Also, NVEs were internalized by lung carcinoma cells and possessed slightly higher toxicity than free CPT. When injected intravenously in balb/c mice, these nanovesicles showed higher retention in blood over 48 h and insignificant accumulation in vital organs like heart and kidneys, thus suggesting its potential for in vivo application. We believe that this system has superior stealth and comparable physicochemical properties to synthetic lipid-based nanocarriers; hence, it can be further developed as personalized medicine.

Block Copolymer Based Nanoparticles for Theranostic Intervention of Cervical Cancer: Synthesis, Pharmacokinetics, and in Vitro/in Vivo Evaluation in HeLa Xenograft Models.

Polymer-based nanoparticles have proven to be viable carriers of therapeutic agents. In this study, we have developed nanoparticles (NPs) from polypeptide-polyethylene glycol based triblock and diblock copolymers. The synthesized block copolymers poly(ethylene glycol)-b-poly(glutamic acid)-b-poly(ethylene glycol) (GEG) and poly(ethylene glycol)-b-poly(glutamic acid) (EG) conjugated with folic acid for targeting specificity (EGFA) have been used to encapsulate methotrexate (MTX) to form M-GEG and M-EGFA NPs aimed at passive and active targeting of cervical carcinoma. In-vitro SRB cytotoxicity and hemolysis assays revealed that these NPs were cytocompatible to healthy human cells and hemocompatible to human RBCs. Cellular uptake by FACS demonstrated their prompt internalization by human cervical carcinoma (HeLa) cells and points toward an apoptotic mechanism of cell kill as confirmed by AO/EB staining as well as histological analysis of explanted HeLa tumors. Pharmacokinetics and biodistribution studies were performed in New Zealand albino rabbits and HeLa xenografted Athymic mice models, respectively, by radiolabeling these NPs with 99mTc. Passive tumor accumulation and active targeting of MTX-loaded polymeric nanoparticles to folate expressing cells were confirmed by intravenous administration of these 99mTc-labeled M-GEG and M-EGFA NPs in HeLa tumor bearing nude mice and clearly visualized by whole-body gamma-SPECT images of these mice. Survival studies of these xenografted mice established the antiproliferative effect of these MTX-loaded NPs while corroborating the targeting effect of folic acid. These studies proved that the M-GEG NPs and M-EGFA NPs could be effective alternatives to conventional chemotherapy along with simultaneous diagnostic abilities and thus potentially viable theranostic options for human cervical carcinoma.

Solid lipid nanoparticles: promising therapeutic nanocarriers for drug delivery.

Development of colloidal delivery systems has opened new avenues/frontiers for improving drug delivery. Solid lipid nanoparticles have come up as the latest development in the arena of lipid based colloidal delivery systems after nanoemulsion and liposomes ever since their introduction in the early 1990s. In this review, the authors have made efforts to bring forth the essential and practically relevant aspects of SLNs. This review gives an overview of the preparation methods of solid lipid nanoparticles while mainly focussing on their biological applications including their projected applications in drug delivery. This review critically examines the influential factors governing the formation of SLNs and then discussing in detail the several techniques being utilized for their characterization. This review discusses the drug loading and drug release aspects of SLNs as these are useful biocompatible carriers of lipophilic and to a certain extent hydrophilic drugs. An updated list of drugs encapsulated into various lipids to prepare SLN formulations has been provided. Other relevant aspects pertaining to the clinical use of SLN formulations like their sterilization and storage stability have also been explained. A unique facet of this review is the discussion on the challenging issues of in vivo applications and recent progresses in overcoming these challenges which follows in the end.

Potential carriers of chemotherapeutic drugs: matrix based nanoparticulate polymeric systems.

In this work matrix based nanoparticulate polymer systems have been designed using the diacrylate derivative of the well-known biocompatible polymer, poly(ethylene glycol) (PEG). This has been crosslinked using bifunctional (ethyleneglycol dimethacrylate) and tetrafunctional (pentaerythritol tetraacrylate) crosslinkers in varied concentrations (10-90%) to result in a polymeric network. The crosslinked polymers thus obtained were characterized by spectroscopic techniques (NMR and FTIR) and then prepared nanoparticles by the nanoprecipitation technique. Particle size analysis showed sizes of ~150 nm (PDI < 1) (with tetrafunctional crosslinker) and ~300 nm (with bifunctional crosslinker). Both the systems however showed unimodal narrow particle size distributions with negative zeta potential values of -15.6 and -7.3 respectively. Cytotoxicity of these formulations was evaluated by MTT assay showing non-cytotoxic nature of these carrier systems. In vitro drug loading and release studies were carried out using a model chemotherapeutic drug, methotrexate(MTX). These MTX loaded nanoformulations have also been evaluated biologically with the help of in vivo studies using radiolabeling techniques (with 99mTc radionuclide). The blood kinetics profile of the formulations was studied on New Zealand Albino rabbits while the biodistribution studies were performed on balb/c mice (with EAT tumours), which revealed a hepatobiliary mode of elimination. These preliminary studies clearly demonstrated the ability of these multifunctional crosslinkers to result in tight nanosized networks with biocompatible polymers such as PEG and their potential to carry chemotherapeutic drugs.