Priyamvada Pradeep

Targeted nanotechnologies for cancer intervention: a patent review (2010-2016)

ABSTRACT Introduction: In recent years, several active targeting nanostrategies have been patented for application in cancer theranostics. The versatility of nanostructures in terms of composition, manufacturability, functionalization, and matrix formation make them ideal for carrying large dose of bioactive contents, high density of targeting ligands on their surface, efficient delivery to the site of interest, and capable of forming multicomponent platforms. Areas covered: The patents were classified into polymeric and non-polymeric nanostructures and their applicability in addressing the targeting paradigm related to cancer intervention was explored. Specialized platforms such as nanoparticles, nanomicelles, nanocomposites, nanotubes, quantum dots, metal/silica particles, and dendrimers were cited as targeted nanostructures along with ligands such as antibody fragments, synthetic peptides, aptamers, small molecules, and folates. Here, we focused on patented targeted nanotechnological advances in recent years (2010–2016). Expert opinion: The formulation and performance prerequisites, available nanomaterial options, fabrication feasibility, and challenges and issues related with regulatory approval and patenting of cancer targeted nanocarriers are reviewed. Future research in this area should focus on clinically relevant bioactive combinations, better metastasis control, integration of imaging and theranostic techniques, predictive animal/pre-clinical models, maximal utilisation of extra- and intracellular tumor microenvironment for drug delivery, and exploring the metabolomic-, proteomic-, and genomic-based personalization of cancer nanomedicine.

“On-The-Spot” Arresting of Chondroitin Sulphate Proteoglycans: Implications for Ovarian Adenocarcinoma Recognition and Intervention

Ovarian Cancer (OC) is one of the leading causes of cancer-associated death among women. The underlying biochemical cause of OC proliferation is usually attributed to the over-expression of Chondroitin Sulphate Proteoglycans (CSPGs) wherein the CS-E subgroup plays a major role in tumor cell proliferation by over-expressing vascular endothelial growth factor (VEGF). We hereby hypothesize that by targeting the OC extracellular matrix using a CS-E-specific antibody, GD3G7, we could provide spatial delivery of crosslinkers and anti-VEGF agents to firstly induce in vivo crosslinking and complexation (arresting) of CS-E into a “biogel mass” for efficient and effective detection, detachment and reduction of tumorous tissue, and secondly inhibit angiogenesis in OC. It is further proposed that the antibody-assisted targeted delivery of CS-E crosslinkers can bind to highly anionic CS-E to form a polyelectrolyte complex to inhibit the formation of ovarian tumor spheroids that are responsible for spheroid-induced mesothelial clearance and progression of OC. The hypothesis also describes the potential in vivo “On-The-Spot” CSPG crosslinkers such as sodium trimetaphosphate (physical crosslinker), 1,12-diaminododecane (chemical crosslinker), poly(ethylene glycol) diglycidyl ether (synthetic polymer), and chitosan (natural polyelectrolyte-forming agent). In conclusion, this hypothesis proposes in vivo spatial crosslinking of CSPGs as a potential theranostic intervention strategy for OC—a first in the field of cancer research.

Hypothesis: apo-lactoferrin-Galantamine Proteo-alkaloid Conjugate for Alzheimer's disease Intervention

Alzheimers disease (AD) is known to be caused by the accumulation of deformed beta amyloid and hyperphosphorylated tau proteins resulting into formation and aggregation of senile plaques and neurofibrillary tangles in the brain. Additionally, AD is associated with the accumulation of iron or metal ions in the brain which causes oxidative stress. Galantamine (Gal) is one of the therapeutic agents that has been approved for the treatment of AD, but still saddled with numerous side effects and could not address the issue of iron accumulation in the brain. The use of metal chelators to address the iron accumulation has not been successful due to toxicity and inability to address the aggregation of the plaques. We therefore hypothesize a combinatorial antioxidant–metal–chelator approach by formulating a single dosage form that has the ability to prevent the formation of free radicals, plaques and accumulation of iron in the brain. This can be achieved by conjugating Gal with apo‐lactoferrin (ApoLf), a natural compound that has high binding affinity for iron, to form an apo‐lactoferrin–galantamine proteo‐alkaloid conjugate (ApoLf–Gal) as a single dosage form for AD management. The conjugation is achieved through self‐assembly of ApoLf which results in encapsulation of Gal. ApoLf changes its conformational structure in the presence of iron; therefore, ApoLf–Gal is proposed to deliver Gal and pick up excess iron when in contact with iron. This strategy has the potential to proffer a dual neuroprotection and neurotherapeutic interventions for the management of AD.

Chemotherapeutic Efficacy of Implantable Antineoplastic-Treatment Protocols in an Optimal Mouse Model for Human Ovarian Carcinoma Cell Targeting

The present study aimed to design and develop a nanocomposite drug delivery system employing an antineoplastic-loaded antibody functionalized nanomicelle encapsulated within a Chitosan–Poly(vinylpyrrolidone)–Poly(N-isopropylacrylamide) (C–P–N) hydrogel to form an in situ forming implant (ISFI), responsive to temperature and pH for cancer cell-targeting following intraperitoneal implantation. The optimum nanomicelle formulation was surface-functionalized with anti-MUC 16 (antibody) for the targeted delivery of methotrexate to human ovarian carcinoma (NIH:OVCAR-5) cells in Athymic nude mice that expressed MUC16, as a preferential form of intraperitoneal ovarian cancer (OC) chemotherapy. The cross-linked interpenetrating C–P–N hydrogel was synthesized for the preparation of an in situ-forming implant (ISFI). Subsequently, the ISFI was fabricated by encapsulating a nanocomposite comprising of anti-MUC16 (antibody) functionalized methotrexate (MTX)-loaded poly(N-isopropylacrylamide)-b-poly(aspartic acid) (PNIPAAm-b-PASP) nanomicelles (AF(MTX)NM’s) within the cross-linked C–P–N hydrogel. This strategy enabled specificity and increased the residence time of the nanomicelles at tumor sites over a period exceeding one month, enhancing uptake of drugs and preventing recurrence and chemo-resistance. Chemotherapeutic efficacy was tested on the optimal ovarian tumor-bearing Athymic nude mouse model and the results demonstrated tumor regression including reduction in mouse weight and tumor size, as well as a significant (p < 0.05) reduction in mucin 16 levels in plasma and ascitic fluid, and improved survival of mice after treatment with the experimental anti-MUC16/CA125 antibody-bound nanotherapeutic implant drug delivery system (ISFI) (p < 0.05). The study also concluded that ISFI could potentially be considered an important immuno-chemotherapeutic agent that could be employed in human clinical trials of advanced, and/or recurring, metastatic epithelial ovarian cancer (EOC). The development of this ISFI may circumvent the treatment flaws experienced with conventional systemic therapies, effectively manage recurrent disease and ultimately prolong disease-free intervals in ovarian cancer patients.

Nanotechnology and Glycosaminoglycans: Paving the Way Forward for Ovarian Cancer Intervention

Ovarian cancer (OC) has gained a great deal of attention due to its aggressive proliferative capabilities, high death rates and poor treatment outcomes, rendering the disease the ultimate lethal gynaecological cancer. Nanotechnology provides a promising avenue to combat this malignancy by the niche fabrication of optimally-structured nanomedicines that ensure potent delivery of chemotherapeutics to OC, employing nanocarriers to act as “intelligent” drug delivery vehicles, functionalized with active targeting approaches for precision delivery of chemotherapeutics to overexpressed biomarkers on cancer cells. Recently, much focus has been implemented to optimize these active targeting mechanisms for treatment/diagnostic purposes employing nanocarriers. This two-part article aims to review the latest advances in active target-based OC interventions, where the impact of the newest antibody, aptamer and folate functionalization on OC detection and treatment is discussed in contrast to the limitations of this targeting mechanism. Furthermore, we discuss the latest advances in nanocarrier based drug delivery in OC, highlighting their commercial/clinical viability of these systems beyond the realms of research. Lastly, in the second section of this review, we comprehensively discussed a focus shift in OC targeting from the well-studied OC cells to the vastly neglected extracellular matrix and motivate the potential for glycosaminoglycans (GAGs) as a more focused extracellular molecular target.

Alternative fluorophores designed for advanced molecular imaging

Fluorescent molecular imaging has advanced drastically over the past decade. With the development of high-resolution microscopy techniques and the ability to visualize intracellular molecular events, there is a growing need for new fluorophores to accompany these fast-developing techniques. Therefore, there has been substantial development of alternative fluorophores for single-molecule detection and molecular imaging. These rationally designed fluorophores have infinite possibilities and novel fluorophores are constantly being produced for different applications. This review focuses on the recent developments in novel fluorophores designed for molecular imaging and single-molecule detection. Here, single-molecule imaging, smart fluorescent probes, two-photon microscopy, Förster resonance energy transfer (FRET) and super-resolution microscopy are discussed in detail.

3-Methyl-1-tosyl-1H-indole-2-carbaldehyde

The title indole derivative, C17H15NO3S, crystallizes with two independent molecules in the asymmetric unit. The benzene ring of the tosyl group is almost perpedicular to the indole ring in both molecules, with interplanar angles of 82.60 (5)° and 81.82 (6)°. The two molecules are, as a consequence, able to form an almost centrosymmetric non-bonded dimer, in which the molecules are linked by pairs of C—H⋯π interactions. The crystal structure displays a three-dimensional network of C—H⋯O interactions. A π–π interaction occurs between inversion-related indole rings with a centroid–centroid distance of 3.6774 (16) Å and an interplanar angle of 1.53 (15)°. This interaction leads to a stacking of molecules along the a axis.