A Path of Novelty from Nanoparticles to Nanobots: Theragnostic Approach for Targeting Cancer Therapy.

Pharmaceutical development of cancer therapeutics is a dynamic area of research. Even after decades of intensive work, cancer continues to be a dreadful disease with an ever-increasing global incidence. The progress of nanotechnology in cancer research has overcome inherent limitations in conventional cancer chemotherapy and fulfilled the need for target-specific drug carriers. Nanotechnology uses the altered patho-physiological microenvironment of malignant cells and offers various advantages like improved solubility, reduced toxicity, prolonged drug circulation with controlled release, circumventing multidrug resistance, and enhanced biodistribution. Early cancer detection has a crucial role in selecting the best drug regime, thus, diagnosis and therapeutics go hand in hand. Furthermore, nanobots are an amazing possibility and promising innovation with numerous significant applications, particularly in fighting cancer and cleaning out blood vessels. Nanobots are tiny robots, ranging in size from 1 to 100 nm. Moreover, the nanobots would work similarly to white blood cells, watching the bloodstream and searching for indications of distress. This review articulates the evolution of various organic and inorganic nanoparticles and nanobots used as therapeutics, along with their pros and cons. It also highlights the shift in diagnostics from conventional methods to more advanced techniques. This rapidly growing domain is providing more space for engineering desired nanoparticles that can show miraculous results in therapeutic and diagnostic trials.

Role of In Vitro Models for Development of Ophthalmic Delivery Systems.

There is emergent need for in vitro models which are physiologically correct, easy to reproduce, and mimic characteristic functionalities of desired tissue, organ, or diseases state for ophthalmic drug screening, as well as disease modeling. To date, a variety of in vitro models have been developed for the applications ranging from 2D cell culture-based monolayers, multilayer, or co-culture models, to 3-dimensional (3D) organoids, 3D printed and organ on chip systems. Each model has its own pros and cons. While simple models are easier to create, and faster to reproduce, they lack recapitulation of the complex framework, functionalities, and properties of tissues or their subunits. Recent advancements in technologies and integration with tissue engineering and involvement of microfluidic systems have offered novel platforms which can better mimic the in vivo microenvironment, thus possessing potential in transformation of ophthalmic drug development. In this review we summarize existing in vitro ocular models while discussing applicability, drawbacks associated with them, and possible future applications.

Role of Exosomes for Delivery of Chemotherapeutic Drugs.

Exosomes are endogenous extracellular vesicles (30-100 nm) composed with membrane lipid bilayer which carry vesicular proteins, enzymes, mRNA, miRNA and nucleic acids. They act as messengers for intra- and inter-cellular communication. In addition to their physiological roles, exosomes have the potential to encapsulate and deliver small chemotherapeutic drugs and biological molecules such as proteins and nucleic acid-based drugs to the recipient tissue or organs. Due to their biological properties, exosomes have better organotropism, homing capacity, cellular uptake and cargo release ability than other synthetic nano-drug carriers such as liposomes, micelles and nanogels. The secretion of tumor-derived exosomes is increased in the hypoxic and acidic tumor microenvironment, which can be used as a target for nontoxic and nonimmunogenic drug delivery vehicles for various cancers. Moreover, exosomes have the potential to carry both hydrophilic and hydrophobic chemotherapeutic drugs, bypass RES effect and bypass BBB. Exosomes can be isolated from other types of EVs and cell debris based on their size, density and specific surface proteins through ultracentrifugation, density gradient separation, precipitation, immunoaffinity interaction and gel filtration. Drugs can be loaded into exosomes at the biogenesis stage or with the isolated exosomes by incubation, electroporation, extrusion or sonication methods. Finally, exosomal cargo vehicles can be characterized by ultrastructural microscopic analysis. In this review we intend to summarize the inception, structure and function of the exosomes, role of exosomes in immunological regulation and cancer, methods of isolation and characterization of exosomes and products under clinical trials. This review will provide an inclusive insight of exosomes in drug delivery.

Chemosensitizing Effect of Cernumidine Extracted from Solanum cernuum on Bladder Cancer Cells in Vitro.

Cernumidine (CER) is a guanidinic alkaloid isolated from Solanum cernuum leaves. In this work, we investigated the cytotoxicity, chemosensitizing effect of cernumidine to cisplatin (cDDP) and the possible mechanism of action of the combination on bladder cancer cells. Cernumidine showed cytotoxicity and could sensitize bladder cancer cells to cisplatin. The combination of CER+cDDP inhibited cell migration on T24 cells. CER+cDDP down-regulated MMP-2/9 and p-ERK1/2, while it increased EGFR activity corroborating the observed cell migration inhibition. Down-regulation of Bcl-2 and up-regulation pro-apoptotic Bax and further depletion of the mitochondrial membrane potential (ΔΨm) indicates that mitochondria play a central role in the combination treatment inducing the mitochondrial signaling pathway of apoptosis in T24 cells. Our data showed that the alkaloid cernumidine is worthy of further studies as a chemosensitizing agent to be used in complementary chemotherapy.

Pharmacokinetic, biodistribution and therapeutic efficacy of 5-fluorouracil-loaded pH-sensitive PEGylated liposomal nanoparticles in HCT-116 tumor bearing mouse.

The objective of the study was to investigate the pharmacokinetics and efficacy of 5-FU entrapped pH-sensitive liposomal nanoparticles with surface-modified anti-epidermal growth factor receptor (EGFR) antibody (pHLNps-5-FU) delivery system. Cytotoxicity of 5-FU and pHLNps-5-FU was determined in vitro against HCT-116 cells. The biodistribution and pharmacokinetic parameters of the administered 5-FU and pHLNps-5-FU as well as efficacy of 5-FU and pHLNps-5-FU were determined in HCT-116 subcutaneous mouse model. Mean size of pHLNp-5-FU was 164.3 ± 8.4 nm with entrapment efficiency (E.E) of 54.17%. While cytotoxicity of 5-FU and pHLNps-5-FU showed a strong dose-dependent, pHLNps-5-FU proved to be more effective (2-3 fold high) than that of 5-FU against HCT-116 cells. Pharmacokinetic study showed a prolonged plasma circulation of pHLNps-5-FU and a more significant body exposure while accumulation of pHLNps-5-FU in tumor was significantly higher than that of free 5-FU. Further, the efficacy of pHLNps-5-FU, was greater than free 5-FU at equivalent 5-FU dose. The study suggests that pHLNps may be an effective drug delivery system to enhance the anticancer activity of 5-FU against colorectal tumor growth.