Anti-Glioma Activity Achieved by Dual Blood-Brain Barrier/Glioma Targeting Naive Chimeric Peptides-Based Co-Assembled Nanophototheranostics

Peptide monomers can either self-assemble with themselves enacting a solo-component assembly or they can co-assemble by interacting with other suitable partners to mediate peptide co-assembly. Peptide co-assemblies represent an innovative class of naive, multifunctional, bio-inspired supramolecular constructs that result in the production of nanostructures with widespread functional, structural, and chemical multiplicity. Herein, the co-assembly of novel chimeric peptides (conjugates of T7 (HAIYPRH)/t-Lyp-1 (CGNKRTR) peptides and aurein 1.2 (GLFDIIKKIAESF)) has been explored as a means to produce glioma theranostics exhibiting combinatorial chemo-phototherapy. Briefly, we have reported here the design and solid phase synthesis of a naive generation of twin-functional peptide drugs incorporating the blood-brain barrier (BBB) and glioma dual-targeting functionalities along with anti-glioma activity (G-Anti G and B-Anti G). Additionally, we have addressed their multicomponent co-assembly and explored their potential application as glioma drug delivery vehicles. Our naive peptide drug-based nanoparticles (NPs) successfully demonstrated a heightened glioma-specific delivery and anti-glioma activity. Multicomponent indocyanine green (ICG)-loaded peptide co-assembled NPs (PINPs: with a hydrodynamic size of 348 nm and a zeta-potential of 5 mV) showed enhanced anti-glioma responses in several cellular assays involving C6 cells. These included a mass demolition with no wound closure (i.e., a 100% cell destruction) and around 63% collaborative chemo-phototoxicity (with both a photothermal and photodynamic effect) after near infrared (NIR) 808 laser irradiation. The dual targeting ability of peptide bioconjugates towards both the BBB and glioma cells, presents new opportunities for designing tailored and better peptide-based nanostructures or nanophototheranostics for glioma.

In-vitro toxicity assessment of a textile dye Eriochrome Black T and its nano-photocatalytic degradation through an innovative approach using Mf-NGr-CNTs-SnO2 heterostructures

The present study aimed to assess the in-vitro toxicity of a popular azodye, Eriochrome Black T (EBT) which may be an environmental hazard causing water pollution if released by textile industries as waste effluents to nearby water ponds. We explored the toxic potential of EBT at 200, 400 and 800 μg/ml concentrations, which were selected based on quantification of EBT present in the pond water near carpet industries. We investigated the permeability of EBT across the organ barriers and found it to be 6.48 ± 0.44% at the highest concentration. EBT also showed up to 26.46 ± 0.533% hemolytic potential on human RBCs. MTT assay revealed toxicity of up to 64.9 ± 10.12%. A dose-dependent increase in intracellular ROS levels and Caspase 3/7 activity was observed and confocal microscopy also demonstrated a similar trend of cellular apoptosis indicating ROS mediated induction of apoptosis as a mechanism of EBT induced cytotoxicity. After establishing the toxicity of EBT, an innovative nano-photocatalytic approach for dye remediation was applied by using as synthesized Mf-NGr-CNTs-SnO₂ heterostructures. This catalyst showed dye degradation potential of up to 82% in 2 h in the presence of sun light. The degraded dye products were tested to have up to 30% reduced cellular toxicity as compared to the parent compound. This work successfully establishes the toxicity of EBT along with devising an innovative approach towards dye degradation where the catalyst is adhered on melamine foam and not being mixed in the effluents directly, thereby, reducing the possibility of catalyst being leached out into the river water.

Near infrared triggered chemo-PTT-PDT effect mediated by glioma directed twin functional-chimeric peptide-decorated gold nanoroses

The successful application of nanomedicine against glioma is basically hooked on to the fabrication of specific and efficient glioma targeted multifunctional theranostics. Herein, through an easy synthetic methodology, we fabricated a type of novel multifunctional theranostic nanoplatform comprising of anisotropic gold nanoroses (AuNs) co-loaded with doxorubicin (DOX) and the near-infrared (NIR) active/responsive dye, indocyanine green (ICG). The tailored nanotheranostics upon being exposed to NIR laser helped in achieving combinatorial chemo-phototherapy along with optical cell imaging. BBB/glioma-targeting ability was realized by amalgamating the AuNs with a naive peptide drug with BBB-glioma targeting and anti-glioma twin functionality. Efficacy studies carried out in C6 cells and spheroids demonstrated heightened synergistic glioma chemo-PDT-PTT effect (~85% ablation in C6 cells and ~88% in C6 spheroids) by the AuNDIPs as compared to the individual therapeutic entities. Here, the AuNs derived nanophototheranostics with in force targeting and on-demand drug release nature will further aid in abolishing chemotherapy associated adverse events by adopting a combinatorial approach for synergistic glioma eradication.

Anti-Amyloidogenic and Fibril-Disaggregating Potency of the Levodopa-Functionalized Gold Nanoroses as Exemplified in a Diphenylalanine-Based Amyloid Model

The phenomenon of proteins/peptide assembly into amyloid fibrils is associated with various neurodegenerative and age-related human disorders. Inhibition of the aggregation behavior of amyloidogenic peptides/proteins or disruption of the pre-formed aggregates is a viable therapeutic option to control the progression of various protein aggregation-related disorders such as Alzheimer's disease (AD). In the current work, we investigated both the amyloid inhibition and disaggregation proclivity of levodopa-functionalized gold nanoroses (GNRs) against various peptide-based amyloid models, including the amyloid beta peptide [Aβ (1-42) and Aβ (1-40)] and the dipeptide phenylalanine-phenylalanine (FF). Our results depicted the anti-aggregation behavior of the GNR toward FF and both forms of Aβ-derived fibrils. The peptides demonstrated a variation in their fiber-like morphology and a decline in thioflavin T fluorescence after being co-incubated with the GNR. We further demonstrated the neuroprotective effects of the GNR in neuroblastoma cells against FF and Aβ (1-42) fiber-induced toxicity, exemplified both in terms of regaining cellular viability and reducing production of reactive oxygen species. Overall, these findings support the potency of the GNR as a promising platform for combating AD.

Dual Blood-Brain Barrier-Glioma Targeting Peptide-Poly(levodopamine) Hybrid Nanoplatforms as Potential Near Infrared Phototheranostic Agents in Glioblastoma

Combined chemo-phototherapy for boosting the efficacy of individual modalities by synergism for antiglioma treatments is in its embryonic stage and far away from effective clinical translation. Herein, moving a step closer, we recommend a facile stratagem to fabricate smart biocompatible and biodegradable multifunctional nanoplatforms comprising inherently fluorescent poly(levodopamine) nanoparticles (FLs) co-loaded with doxorubicin (DOX) and indocyanine green (ICG). The designed near-infrared (NIR) phototheranostic agents upon NIR laser irradiation helped precipitate combined chemo-phototherapy [both photothermal therapy (PTT) and photodynamic therapy (PDT)] and optical imaging under one roof. Excellent glioma-targeting ability was allocated to the nanoplatforms by conjugating them with a novel chimeric therapeutic peptide with glioma homing and antiglioma dual functionality. Further, DOX/ICG/peptide co-loaded nanoplatforms (FLDIPs) exhibited triggered drug release in response to multiple stimuli. Studies performed in 2D C6 glioma cells and 3D spheroids exhibited superior combined chemo-PDT/PTT effects (∼94% killing in cells and ∼87% in spheroids) of the designed FL based nanoplatforms compared to individual therapeutic components. Herein, the FL based multifunctional nanoplatforms with active targeting ability and stimuli responsive drug release behavior will further help in nullifying chemotherapy based adverse effects and mitigate chemo-resistance by adopting a combinatorial approach.

Repurposed Drugs, Molecular Vaccines, Immune-Modulators, and Nanotherapeutics to Treat and Prevent COVID-19 Associated with SARS-CoV-2, a Deadly Nanovector

The deadly pandemic, coronavirus disease 2019 (COVID-19), caused due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has paralyzed the world. Although significant methodological advances have been made in the field of viral detection/diagnosis with 251 in vitro diagnostic tests receiving emergency use approval by the US-FDA, little progress has been made in identifying curative or preventive therapies. This review discusses the current trends and potential future approaches for developing COVID-19 therapeutics, including repurposed drugs, vaccine candidates, immune-modulators, convalescent plasma therapy, and antiviral nanoparticles/nanovaccines/combinatorial nanotherapeutics to surmount the pandemic viral strain. Many potent therapeutic candidates emerging via drug-repurposing could significantly reduce the cost and duration of anti-COVID-19 drug development. Gene/protein-based vaccine candidates that could elicit both humoral and cell-based immunity would be on the frontlines to prevent the disease. Many emerging nanotechnology-based interventions will be critical in the fight against the deadly virus by facilitating early detection and enabling target oriented multidrug therapeutics. The therapeutic candidates discussed in this article include remdesivir, dexamethasone, hydroxychloroquine, favilavir, lopinavir/ritonavir, antibody therapeutics like gimsilumab and TJM2, anti-viral nanoparticles, and nanoparticle-based DNA and mRNA vaccines.

l-3,4-Dihydroxyphenylalanine templated anisotropic gold nano/micro-roses as potential disrupters/inhibitors of α-crystallin protein and its gleaned model peptide aggregates

Cataract, the major cause of blindness worldwide occurs due to the misfolding and aggregation of the protein crystallin, which constitute a major portion of the lens protein. Other than the whole protein crystallin, the peptide sequences generated from crystallin as a result of covalent protein damage have also been shown to possess and foster protein aggregation, which can be established as crystallin aggregation models. Thus, the disaggregation or inhibition of these protein aggregates could be a viable approach to combat cataract and preserve lens proteostasis. Herein, we tried to explore the disruption as well as inhibition of the intact α-crystallin protein and α-crystallin derived model peptide aggregates by l-3,4-dihydroxyphenylalanine (levodopa) coated gold (Au) nano/micro-roses as modulators. Thioflavin T fluorescence enhancement assay, and electron microscopic analysis were being employed to probe the anti-aggregation behavior of the Au nano/micro-roses towards the aggregating α-crystallin peptides/protein. Further, computational studies were performed to reveal the nature of molecular interactions between the levodopa molecule and the α-crystallin derived model peptides. Interestingly, both levodopa coated Au nano/micro-roses were found to be capable of inhibiting as well as preventing the aggregation of the intact α-crystallin protein and other model peptides derived from it.

Sewage Effluent Causes Metal Pollution of a Sub-tropical River System in Zimbabwe

Metal pollutants are persistent in the environment and of concern to human health. The aim of the study was to assess the distribution of metals (Cr, Fe, Pb, Mg and Cu) in Sebakwe River. Water and sediment samples were collected from upstream reference sites (4 and 5) and influenced downstream sites (1, 2 and 3) of the sewage effluent discharge point. Pb concentrations in water were significantly higher (p < 0.05) in sites 1 and 2 downstream of the sewage discharge point. In the sediments, the sites downstream of the effluent discharge point had significantly higher concentrations of Cu (p < 0.05) and Cr (p < 0.05). A comparison of metal concentration in water with World Health Organization and Standards Association of Zimbabwe standards revealed that the levels of Pb in water were above the recommended limits, posing a health risk to Pb poisoning for people living along Sebakwe River.

Nanotheranostics, a future remedy of neurological disorders

INTRODUCTION

Effective therapy of various neurological disorders is hindered on account of the failure of various therapeutics crossing blood-brain-barrier (BBB). Nanotheranostics has emerged as a cutting-edge unconventional theranostic nanomedicine, capable of realizing accurate diagnosis together with effective and targeted delivery of therapeutics across BBB to the unhealthy regions of the brain for potential clinical success.

AREAS COVERED

We have tried to review the current status of nanotheranostic based approaches followed to manage neurological disorders. The focus has been majorly laid on to explore various theranostic nanoparticles and their application potential towards image-guided neurotherapies. Additionally, the usefulness of exceptional diagnostic, imaging techniques including magnetic resonance imaging and fluorescence imaging are being discussed by highlighting their promising opportunities in the detection, diagnosis, and treatment of the neurological disorders.

EXPERT OPINION

Inimitable diagnostic and therapeutic potential of nanotheranostics have accomplished the aim of personalized therapies by governing the therapeutic efficacy of the system along with facilitating patient pre-selection grounded on non-invasive imaging, thereby predicting the responses of patients to nanomedicine treatments. While these accomplishments are encouraging, they are still the minority and demands for a continuous effort to improve sensitivity and precision in screening/diagnosis along with improving therapeutic efficacy in various neural disorders.

Receptor Targeted Polymeric Nanostructures Capable of Navigating across the Blood-Brain Barrier for Effective Delivery of Neural Therapeutics

The window of neurological maladies encompasses 600 known neurological disorders. In the past few years, an inordinate upsurge in the incidences of neuronal ailments with increased mortality rate has been witnessed globally. Despite noteworthy research in the discovery and development of neural therapeutics, brain drug delivery still encounters limited success due to meager perviousness of most of the drug molecules through the blood-brain barrier (BBB), a tight layer of endothelial cells that selectively impedes routing of the molecules across itself. In this Review, we have tried to present a comprehensive idea on the recent developments in nanoparticle based BBB delivery systems, with a focus on the advancements in receptor targeted polymeric nanoparticles pertaining to BBB delivery. We have also attempted to bridge the gap between conventional brain delivery strategies and nanoparticle based BBB delivery for in-depth understanding. Various strategies are being explored for simplifying delivery of molecules across the BBB; however, they have their own limitations such as invasiveness and need for hospitalization and surgery. Introduction of nanotechnology can impressively benefit brain drug delivery. Though many nanoparticles are being explored, there are still several issues that need to be analyzed scrupulously before a real and efficient BBB traversing nanoformulation is realized.

Prevalence and the correlates of postnatal depression in an urban high density suburb of Harare

INTRODUCTION

Postnatal depression is a common cause of morbidity but is rarely diagnosed or managed in busy primary care settings in most resource limited countries like Zimbabwe.

OBJECTIVES

This study sought to determine the prevalence of postnatal depression and establish factors associated with postnatal depression.

METHODS

The study utilized a cross-sectional descriptive design where 295 consenting women (mean age=25.4 years; SD= 5.6 years) attending post natal care services at Mbare Polyclinic were recruited. Data were collected using the validated Shona version of the Edinburgh Postnatal Depression Scale (EPDS) questionnaire. Associations between variables were computed using the chi-square test statistic and where appropriate the Fisher’s exact statistic.

RESULTS

Prevalence for postnatal depression was 34.2% among women in the study. Univariate analysis revealed that there were no statistically significant associations between mother’s age (p=0.120), parity (p=0.396), marital status (p=0.523), level of education (p=0.805), and age of child (p=0.489) and postnatal depression.

CONCLUSION

Findings from this study indicate that there is a high prevalence of postnatal depression in women in Mbare, Zimbabwe. This therefore calls for further studies to identify and address the causes of postnatal depression among women attending postnatal care in Zimbabwe.