Role of NLRP3 inflammasome in nanoparticle adjuvant-mediated immune response.

The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome is pivotal in orchestrating the immune response induced by nanoparticle adjuvants. Understanding the intricate mechanisms underlying the activation of NLRP3 inflammasome by these adjuvants is crucial for deciphering their immunomodulatory properties. This review explores the involvement of the NLRP3 inflammasome in mediating immune responses triggered by nanoparticle adjuvants. It delves into the signaling pathways and cellular mechanisms involved in NLRP3 activation, highlighting its significance in modulating the efficacy and safety of nanoparticle-based adjuvants. A comprehensive grasp of the interplay between NLRP3 inflammasome and nanoparticle adjuvants holds promise for optimizing vaccine design and advancing immunotherapeutic strategies.

Postsynaptic receptors regulate presynaptic transmitter stability through transsynaptic bridges.

Stable matching of neurotransmitters with their receptors is fundamental to synapse function and reliable communication in neural circuits. Presynaptic neurotransmitters regulate the stabilization of postsynaptic transmitter receptors. Whether postsynaptic receptors regulate stabilization of presynaptic transmitters has received less attention. Here, we show that blockade of endogenous postsynaptic acetylcholine receptors (AChR) at the neuromuscular junction destabilizes the cholinergic phenotype in motor neurons and stabilizes an earlier, developmentally transient glutamatergic phenotype. Further, expression of exogenous postsynaptic gamma-aminobutyric acid type A receptors (GABAA receptors) in muscle cells stabilizes an earlier, developmentally transient GABAergic motor neuron phenotype. Both AChR and GABAA receptors are linked to presynaptic neurons through transsynaptic bridges. Knockdown of specific components of these transsynaptic bridges prevents stabilization of the cholinergic or GABAergic phenotypes. Bidirectional communication can enforce a match between transmitter and receptor and ensure the fidelity of synaptic transmission. Our findings suggest a potential role of dysfunctional transmitter receptors in neurological disorders that involve the loss of the presynaptic transmitter.

Generalized fear after acute stress is caused by change in neuronal cotransmitter identity.

Overgeneralization of fear to harmless situations is a core feature of anxiety disorders resulting from acute stress, yet the mechanisms by which fear becomes generalized are poorly understood. In this study, we show that generalized fear in mice results from a transmitter switch from glutamate to γ-aminobutyric acid (GABA) in serotonergic neurons of the lateral wings of the dorsal raphe. Similar change in transmitter identity was found in the postmortem brains of individuals with posttraumatic stress disorder (PTSD). Overriding the transmitter switch in mice prevented the acquisition of generalized fear. Corticosterone release and activation of glucocorticoid receptors mediated the switch, and prompt antidepressant treatment blocked the cotransmitter switch and generalized fear. Our results provide important insight into the mechanisms involved in fear generalization.

Canine ocular thelaziosis: first report in Andhra Pradesh.

Thelaziosis is a vector-borne zoonotic disease with worldwide distribution, including in India and reports on canine ocular thelaziosis are very limited. The present case documentation will provide basic information to initiate the geographical epidemiological studies which will help to prevent the spread to these zoonotic diseases in the specified location. This communication reports about the rare case of canine ocular thelaziosis in Andhra Pradesh with the morphological features of the parasite and the management of ocular manifestations with suitable antimicrobial and anti-inflammatory eye drops along with ivermectin injections.

Generalized fear following acute stress is caused by change in co-transmitter identity of serotonergic neurons.

Overgeneralization of fear to harmless situations is a core feature of anxiety disorders resulting from acute stress, yet the mechanisms by which fear becomes generalized are poorly understood. Here we show that generalized fear in mice in response to footshock results from a transmitter switch from glutamate to GABA in serotonergic neurons of the lateral wings of the dorsal raphe. We observe a similar change in transmitter identity in the postmortem brains of PTSD patients. Overriding the transmitter switch in mice using viral tools prevents the acquisition of generalized fear. Corticosterone release and activation of glucocorticoid receptors trigger the switch, and prompt antidepressant treatment blocks the co-transmitter switch and generalized fear. Our results provide new understanding of the plasticity involved in fear generalization.

Recent Advances in the Lipid Nanoparticle-Mediated Delivery of mRNA Vaccines.

Lipid nanoparticles (LNPs) have recently emerged as one of the most advanced technologies for the highly efficient in vivo delivery of exogenous mRNA, particularly for COVID-19 vaccine delivery. LNPs comprise four different lipids: ionizable lipids, helper or neutral lipids, cholesterol, and lipids attached to polyethylene glycol (PEG). In this review, we present recent the advances and insights for the design of LNPs, as well as their composition and properties, with a subsequent discussion on the development of COVID-19 vaccines. In particular, as ionizable lipids are the most critical drivers for complexing the mRNA and in vivo delivery, the role of ionizable lipids in mRNA vaccines is discussed in detail. Furthermore, the use of LNPs as effective delivery vehicles for vaccination, genome editing, and protein replacement therapy is explained. Finally, expert opinion on LNPs for mRNA vaccines is discussed, which may address future challenges in developing mRNA vaccines using highly efficient LNPs based on a novel set of ionizable lipids. Developing highly efficient mRNA delivery systems for vaccines with improved safety against some severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants remains difficult.

Exploring temozolomide encapsulated PEGylated liposomes and lyotropic liquid crystals for effective treatment of glioblastoma: in-vitro, cell line, and pharmacokinetic studies.

Temozolomide (TMZ) is one of the best choices for treating glioblastoma. However, due to the short plasma half-life, only 20-30 % brain bioavailability can be achieved using traditional formulations. In the present study, PEGylated liposomes and lyotropic liquid crystals (LLCs) were developed and investigated to prolong the plasma circulation time of TMZ. Industrially feasible membrane extrusion and modified hot melt emulsification techniques were utilized during the formulation. Liposomes and LLCs in the particle size range of 80-120 nm were obtained with up to 50 % entrapment efficiency. The nanocarriers were found to show a prolonged release of up to 72 h. The cytotoxicity studies in glioblastoma cell lines revealed a âˆ¼1.6-fold increased cytotoxicity compared to free TMZ. PEGylated liposomes and PEGylated LLCs were found to show a 3.47 and 3.18-fold less cell uptake in macrophage cell lines than uncoated liposomes and LLCs, respectively. A 1.25 and 2-fold increase in the plasma t1/2 was observed with PEGylated liposomes and PEGylated LLCs, respectively, compared to the TMZ when administered intravenously. Extending plasma circulation time of TMZ led to significant increase in brain bioavailability. Overall, the observed improved pharmacokinetics and biodistribution of TMZ revealed the potential of these PEGylated nanocarriers in the efficient treatment of glioblastoma.

Overcoming drug resistance with a docetaxel and disulfiram loaded pH-sensitive nanoparticle.

Previous studies have demonstrated that breast cancer cells deploy a myriad array of strategies to thwart the activity of anticancer drugs like docetaxel (DTX), including acquired drug resistance due to overexpression of drug-efflux pumps like P-glycoprotein (P-gp) and innate drug resistance by cancer stem cells (CSCs). As disulfiram (DSF) can inhibit both P-gp and CSCs, we hypothesized that co-treatment of DTX and DSF could sensitize the drug-resistant breast cancer cells. To deliver a fixed dose ratio of DTX and DSF targeted to the tumor, a tumor extracellular pH-responsive nanoparticle (NP) was developed using a histidine-conjugated star-shaped PLGA with TPGS surface decoration ([DD]NpH-T). By releasing the encapsulated drugs in the tumor microenvironment, pH-sensitive NPs can overcome the tumor stroma-based resistance against nanomedicines. In in-vitro studies, [DD]NpH-T exhibited increased drug release at pH 6.8, improved penetration in a 3D tumor spheroid, reduced serum protein adsorption, and enhanced cytotoxic efficacy against both innate and acquired DTX-resistant breast cancer cells. In in-vivo studies, a significant increase in plasma AUC and tumor drug delivery was observed with [DD]NpH-T, which resulted in an enhanced in-vivo anti-tumor efficacy against a mouse orthotopic breast cancer, with a significantly increased intratumoral ROS and apoptosis, while decreasing P-gp expression and prevention of lung metastasis. Altogether, the current study demonstrated that the DTX and DSF combination could effectively target multiple drug-resistance pathways in-vitro, and the in-vivo delivery of this drug combination using TPGS-decorated pH-sensitive NPs could increase tumor accumulation, resulting in improved anti-tumor efficacy.

Breaking the niche: multidimensional nanotherapeutics for tumor microenvironment modulation.

Most of the current antitumor therapeutics were developed targeting the cancer cells only. Unfortunately, in the majority of tumors, this single-dimensional therapy is found to be ineffective. Advanced research has shown that cancer is a multicellular disorder. The tumor microenvironment (TME), which is made by a complex network of the bulk tumor cells and other supporting cells, plays a crucial role in tumor progression. Understanding the importance of the TME in tumor growth, different treatment modalities have been developed targeting these supporting cells. Recent clinical results suggest that simultaneously targeting multiple components of the tumor ecosystem with drug combinations can be highly effective. This type of "multidimensional" therapy has a high potential for cancer treatment. However, tumor-specific delivery of such multi-drug combinations remains a challenge. Nanomedicine could be utilized for the tumor-targeted delivery of such multidimensional therapeutics. In this review, we first give a brief overview of the major components of TME. We then highlight the latest developments in nanoparticle-based combination therapies, where one drug targets cancer cells and other drug targets tumor-supporting components in the TME for a synergistic effect. We include the latest preclinical and clinical studies and discuss innovative nanoparticle-mediated targeting strategies.

Drug-induced change in transmitter identity is a shared mechanism generating cognitive deficits.

Cognitive deficits are a long-lasting consequence of drug use, yet the convergent mechanism by which classes of drugs with different pharmacological properties cause similar deficits is unclear. We find that both phencyclidine and methamphetamine, despite differing in their targets in the brain, cause the same glutamatergic neurons in the medial prefrontal cortex to gain a GABAergic phenotype and decrease their expression of the vesicular glutamate transporter. Suppressing the drug-induced gain of GABA with RNA-interference prevents the appearance of memory deficits. Stimulation of dopaminergic neurons in the ventral tegmental area is necessary and sufficient to produce this gain of GABA. Drug-induced prefrontal hyperactivity drives this change in transmitter identity. Returning prefrontal activity to baseline, chemogenetically or with clozapine, reverses the change in transmitter phenotype and rescues the associated memory deficits. The results reveal a shared and reversible mechanism that regulates the appearance of cognitive deficits upon exposure to different drugs.

Protein fibril assisted chiral assembly of gold nanorods.

Template mediated assembly of plasmonic nanomaterials is a promising approach to induce chirality. Naturally occurring macromolecules can self-assemble to form chiral superstructures, with dimensions extending from nanometer to micrometer length scales. These structures can serve as templates for host plasmonic nanomaterials on their surface through a variety of interactions. The arrangement of nanomaterials on these structures results in a transfer of symmetry from these templates to nanomaterials, which finally generates a chiral response in circular dichroism (CD) spectroscopy. For biosensing and in vitro applications of chiral plasmonics, long-term stability of these templates will be crucial for this approach of chirality induction. Here, we have demonstrated how protein amyloid fibrils can be used as templates to generate a chiroptical response with plasmonic nanomaterials. The temperature and ionic strength of the solution were carefully altered to convert the three-dimensional protein structure into amyloid fibrils. Changes in solution conditions affected the amyloid geometry, long-term stability, and interaction with AuNRs. The modified interactions influenced the orientation of the AuNRs, which affected the intensity of the CD response. The MTT assay indicated that the chiral AuNRs exhibited considerable cell viability, making them ideal for in vivo applications.

pH-Responsive Nanoparticles for Multidimensional Combined Chemo-Immunotherapy of Cancer.

Current research has demonstrated that tumor development and progression are dependent on a multi-cellular interactome, which forms the tumor microenvironment. Multiple components of this multi-cellular ecosystem need to be targeted simultaneously for successful cancer therapy. The objective of this study was to develop a multidimensional combined chemo-immunotherapeutic modality for effective breast cancer treatment. TLR 7/8 agonist resiquimod was identified as a potent macrophage stimulant in an initial screening. To deliver paclitaxel as a chemotherapeutic drug and resiquimod as an immune activator in a tumor-targeted fashion, two different pH-sensitive nanoparticles were synthesized using two different polymers, a linear PLGA and a multi-arm, star-shaped PLGA. The star-PLGA pH-responsive nanoparticles exhibited improved pH-dependent drug release and increased penetration in a complex breast cancer spheroid model (breast cancer cell + macrophage cell). Treatment with paclitaxel and resiquimod encapsulated in the pH-responsive nanoparticles resulted in increased cancer cell death and macrophage activation, as tested in an in-vitro breast cancer spheroid model. Altogether, the current study suggests that the paclitaxel and resiquimod combination has potent chemo-immunotherapeutic activity, and delivery using a pH-sensitive nanoparticle further improves its efficacy.

Development of an in-situ forming, self-healing scaffold for dermal wound healing: in-vitro and in-vivo studies.

The importance of the extra-cellular matrix (ECM) for wound healing has been extensively researched. Understanding its importance, multiple ECM mimetic scaffolds have been developed. However, the majority of such scaffolds are prefabricated. Due to their stiffness, prefabricated scaffolds cannot come into direct contact with the basal skin cells at the wound bed, limiting their efficacy. We have developed a unique wound dressing, using chitosan (CH) and chondroitin sulfate (CS), that can form a porous scaffold (CH-CS PEC) in-situ, at the wound site, by simple mixing of the polymer solutions. As CH is positively and CS is negatively charged, mixing these two polymer solutions would lead to electrostatic cross-linking between the polymers, converting them to a porous, viscoelastic scaffold. Owing to the in-situ formation, the scaffold can come in direct contact with the cells at the wound bed, supporting their proliferation and biofunction. In the present study, we confirmed the cross-linked scaffold formation by solid-state NMR, XRD, and TGA analysis. We have demonstrated that the scaffold had a high viscoelastic property, with self-healing capability. Both keratinocyte and fibroblast cells exhibited significantly increased migration and functional markers expression when grown on this scaffold. In the rat skin-excisional wound model, treatment with the in-situ forming CH-CS PEC exhibited enhanced wound healing efficacy. Altogether, this study demonstrated that mixing CH and CS solutions lead to the spontaneous formation of a highly viscoelastic, porous scaffold, which can support epidermal and dermal cell proliferation and bio-function, with an enhanced in-vivo wound healing efficacy.

Design, Synthesis, and Biological Evaluation of Novel Multifunctional Rolipram-Tranilast Hybrids As Potential Treatment for Traumatic Brain Injury.

Traumatic brain injury (TBI) is a prevalent public healthcare concern frequently instigated by mechanical shock, traffic, or violence incidents, leading to permanent nerve damage, and there is no ideal treatment for it yet. In this study, a series of Rolipram-Tranilast hybrids were designed and synthesized. The neuroprotective activities of the Rolipram-Tranilast hybrids were evaluated both in vitro and in vivo. Compound 5 has been identified as the strongest neuroprotective molecule among the series with robust anti-oxidant and anti-inflammatory potentials. Compound 5 significantly increased the heme oxygenase-1 (HO-1) levels and the phosphorylated cAMP response elements binding protein (p-CREB) while it down-regulated phosphodiesterase-4 B (PDE4B) expression in vitro. Furthermore, compound 5 remarkably attenuated TBI and had a good safety profile in mice. Taken together, our findings suggested that compound 5 could serve as a novel promising lead compound in the treatment of TBI and other central nervous system (CNS) diseases associated with PDE4B and oxidative stress.

Disulfiram potentiates docetaxel cytotoxicity in breast cancer cells through enhanced ROS and autophagy.

BACKGROUND: Recent studies have demonstrated that autophagy plays a critical role in reducing the drug sensitivity of docetaxel (DTX) therapy. Disulfiram (DSF) has exhibited potent autophagy inducing activity in multiple studies. We hypothesized that DSF co-treatment could sensitize breast cancer cells to DTX therapy via autophagy modulation. METHODS: Breast cancer cells, MCF7, and 4T1, were treated with DTX and DSF, alone and in combination. The effects were analyzed by evaluating cytotoxicity, induction of apoptosis, induction of autophagy, and reactive oxygen species (ROS) generation. In addition, the consequence of autophagy and ROS inhibition on the DTX + DSF mediated cytotoxicity was also evaluated. RESULTS: Significant synergism in cytotoxicity was observed with DTX + DSF combination in breast cancer cells, MCF7, and 4T1. Hyper induction of ROS and autophagy was also found with the combination treatment. ROS inhibition by N-Acetyl Cysteine (NAC), as well as autophagy inhibition by ATG5 silencing significantly reduced the autophagy level as well as cytotoxicity of the DTX + DSF combination, indicating that the induction of autophagy mediated by high ROS generation played a critical role behind the synergistic cytotoxicity. CONCLUSIONS: This study indicates that DTX + DSF combination therapy can effectively sensitize cancer cells by hyper inducing autophagy through ROS generation and can be developed as a therapeutic strategy for cancer treatment in the future.

Selective Neck Dissection Technique in the Treatment of Recurrent Pyriform Sinus Fistula.

The 3rd and 4th branchial arch fistulas are rare conditions which are due to embryological persistence or incomplete developmental anomalies. They have a typical course as described by the embryological development but the presentation of cases with true course as per embryology is rare. These patients usually present with repeated infections, inadequate surgical interventions and recurrences. We present two index cases of 3rd and 4th pyriform sinus fistulas with their varied anatomical course and clinical presentation who were treated by selective neck dissection technique.

Chitosan-Chondroitin sulfate based polyelectrolyte complex for effective management of chronic wounds.

Acute and chronic wound remain an unresolved clinical problem among various demographic groups. Traditional marketed products focus mainly on inhibition of bacterial growth at the wound site neglecting the tissue repair, which significantly affect the healing rate. It would be highly beneficial if a wound healing material can be developed which has both antibacterial as well as tissue regenerating potential. We have prepared a polyelectrolyte complex (PEC) using chitosan (CH) and chondroitin sulfate (CS) which can form an in-situ scaffold by spontaneous mixing. The fabrication of CH-CS PEC was optimized using Quality-By-Design (QbD) approach. The prepared PEC showed very high swelling and porosity property. It was found to be non-hemolytic with good blood compatibility and low blood clotting index. It also exhibited good antibacterial activity against both gram-positive and gram-negative bacteria. The cell proliferation study exhibited good cytocompatibility and almost four-fold increase in cell density when treated with CH-CS PEC compared to control. In summary, we demonstrated that the prepared CH-CS PEC showed good blood compatibility, high antibacterial effect, and promoted wound healing potentially by stimulating fibroblast growth, making it an ideal wound dressing material.