SiRNA is a promising therapeutic solution to address gene overexpression or mutations as a post-transcriptional gene regulation process for several pathological conditions such as viral infections, cancer, genetic disorders, and autoimmune disorders like arthritis. This therapeutic method is currently being actively pursued in cancer therapy because siRNA has been found to suppress the oncogenes and address mutations in tumor suppressor genes and elucidate the key molecules in cellular pathways in cancer. It is also effective in personalized gene therapy for several diseases due to its specificity, adaptability, and broad targeting capability. However, naked siRNA is unstable in the bloodstream and cannot efficiently cross cell membranes besides being immunogenic. Therefore, careful design of the delivery systems is essential to fully utilize the potential of this therapeutic solution. This review presents a comprehensive update on the challenges of siRNA delivery and the current strategies used to develop nanoparticulate delivery systems.

Triple negative breast cancer (TNBC) is a difficult to treat disease due to the absence of the three unique receptors estrogen, progesterone and herceptin-2 (HER-2). To improve the current therapy and overcome the resistance of TNBC, there is unmet need to develop an effective targeted therapy. In this regard, one of the logical and economical approaches is to develop a tumor hypoxia-targeting drug formulation platform for selective delivery of payload to the drug-resistant and invasive cell population of TNBC tumors. Toward this, we developed a Carbonic Anhydrase IX (CA IX) receptor targeting human serum albumin (HSA) carriers to deliver the potent anticancer drug, Paclitaxel (PTX). We used Acetazolamide (ATZ), a small molecule ligand of CA IX to selectively deliver HSA-PTX in TNBC cells. A novel method of synthesis involving copper free ‘click’ chemistry (Dibenzocyclooctyl, DBCO) moiety with an azide-labeled reaction partner, known as Strain-Promoted Alkyne Azide Cycloaddition (SPAAC) along with a desolvation method for PTX loading were used in the present study to arrive at the CA IX selective nano-carriers, HSA-PTX-ATZ. The anticancer effect of HSA-PTX-ATZ is higher compared to HSA, PTX and non-targeted HSA-PTX in MDA-MB-231 and MDA-MB-468 cells. The cell killing effect is associated with induction of early and late phases of apoptosis. Overall, our proof-of-concept study shows a promising avenue for hypoxia-targeted drug delivery that can be adapted to several types of cancers.

Triple-Negative Breast Cancer (TNBC) is considered as the most onerous cancer subtype, lacking the estrogen, progesterone, and HER2 receptors. Evaluating new markers is an unmet need for improving targeted therapy against TNBC. TNBC depends on several factors, including hypoxia development, which contributes to therapy resistance, immune evasion, and tumor stroma formation. In this study, we studied the curcumin analogue (3,4-Difluorobenzylidene Curcumin; CDF) encapsulated bovine serum albumin (BSA) nanoparticle for tumor targeting. For tumor targeting, we conjugated Acetazolamide (ATZ) with CDF and encapsulated it in the BSA to form a nanoparticle (namely BSA-CDF-ATZ). The in vitro cytotoxicity study suggested that BSA-CDF-ATZ is more efficient when compared to free CDF. The BSA-CDF-ATZ nanoparticles showed significantly higher cell killing in hypoxic conditions compared to normoxic conditions, suggesting better internalization of the nanoparticles into cancer cells under hypoxia. Fluorescent-dye labeled BSA-CDF-ATZ revealed higher cell uptake of the nanoparticle compared to free dye indicative of better delivery, substantiated by a high rate of apoptosis-mediated cell death compared to free CDF. The significantly higher tumor accumulation and low liver and spleen uptake in TNBC patient-derived tumor xenograft models confirm the significant potential of BSA-CDF-ATZ for targeted TNBC imaging and therapy.

Triple-negative breast cancer (TNBC) is amongst the most challenging tumor subtypes because it presents itself without the estrogen, progesterone, and HER2 receptors. Hence, assessing new markers is an essential requirement for enhancing its targeted treatment. The survival of TNBC relies upon the advancement of hypoxia that contributes to treatment resistance, immune response resistance, and tumor stroma arrangement. Here, we explored bovine serum albumin (BSA) nanoparticle encapsulating the anti-cancer drug Paclitaxel (PTX) for cell-killing mediated by tumor hypoxia. For targeting hypoxia, we conjugated Acetazolamide (ATZ) with BSA nanoparticle that encapsulated PTX (referred hereon as BSA-PTX-ATZ) utilizing copper-free click chemistry, specifically the Strain-Promoted Alkyne Azide Cycloaddition (SPAAC). The in-vitro cell killing study uncovered that BSA-PTX-ATZ is more productive contrasted with free PTX. The evaluations of the physio-chemical properties of BSA-PTX-ATZ proves that the shelf-life is approximately two months when stored either at room or freezing temperatures or under refrigerated conditions. There is no leakage of PTX from the formulation during that period, while their nanoparticulate nature remained undisturbed. The BSA-PTX-ATZ nanoparticles indicated altogether higher cell killing in hypoxic conditions contrasted with normoxia proposing the hypoxia-mediated delivery mechanism of the activity of the formulation. Higher cell uptake found with fluorescent-marked BSA-PTX-ATZ shows CA-IX mediated cell uptake, substantiated by the prominent apoptotic cell death contrasted with free PTX.

Introduction: Alzheimer’s disease (AD) the most common form of dementia worldwide, that affects older population and the 6 ^th leading cause of death in USA. The cost of care involved is about $234 billion. AD is marked by the presence of beta‐amyloid protein plaques outside neurons that leads to cell death and the accumulation of an abnormal intracellular neurofibrillar tangles of hyper phosphorylated τ (tau) protein. This undesired accumulation causes obstruction of nutrition and other essential molecules to the brain. There is no potential treatment in the clinic because of the lack of proper understanding of the pathogenesis, delivery challenges across the Blood‐Brain‐Barrier (BBB), and unfavorable immune responses. Challenge: In the present research we are developing ultra‐small nanoparticles (USNPs), that are expected to (i) Enhance the circulation half‐life and minimize the side effect of therapeutics; (ii) enable transport of therapeutics across the BBB and promote their accumulation in the desired brain region; (iii) assist in reduction and clearance of beta amyloid plaques; and (iv) promote favorable immune response. In addition when USNPs are combined with an NIR‐dye it may function as a diagnostic agent. In order to test our hypothesis, we designed a new Lactoferrin (Lf) based USNP to target low‐density lipoprotein receptor‐related protein‐1 (LRP‐1) overexpressed in AD. Results: The TEM analysis showed well‐defined spherical Lf NPs with an ultra‐small size of ~ 20–30 nm that will allow efficient penetration/delivery across the BBB. Further, the data obtained from our preliminary studies in SH‐SY5Y and BV2 brain cells suggest a dose‐dependent cell uptake of DiD‐fluorescence labeled Lf NPs. The cytotoxicity assays on normal brain cells showed them to be safe/non‐cytotoxic with a cell viability around ~ 85–90%. Subsequently, Tauopathy was induced employing okadoic acid in SH‐SY5Y cells to mimic AD under in vitro conditions. This was followed by testing of various combinations of the protein kinase inhibitors to assess the efficacy of the combination therapy on the hyper phosphorylation of Tau protein (pTau) in the brain cells. We also developed conditioned BBB cell culture model to demonstrate the penetration of Lf USNP across the BBB. Our IHC data reveal that it can be used to deliver combination of protein kinase inhibitors into the brain to reduce the tau tangle formation. Thus far, our hypothesis is being supported by the observed results. Conclusion: The preliminary results looks very promising in the direction of AD combination therapy. The outcome for our study protend to provide a strong rationale to employ Lf USNPs to overcome the BBB for improved AD targeting of the drugs, leading to better therapy outcome.