Drug instillation via a topical route is preferred since it is desirable and convenient due to the noninvasive and easy drug access to different segments of the eye for the treatment of ocular ailments. The low dose, rapid onset of action, low or no toxicity to the local tissues, and constrained systemic outreach are more prevalent in this route. The majority of ophthalmic preparations in the market are available as conventional eye drops, which rendered <5% of a drug instilled in the eye. The poor drug availability in ocular tissue may be attributed to the physiological barriers associated with the cornea, conjunctiva, lachrymal drainage, tear turnover, blood–retinal barrier, enzymatic drug degradation, and reflex action, thus impeding deeper drug penetration in the ocular cavity, including the posterior segment. The static barriers in the eye are composed of the sclera, cornea, retina, and blood–retinal barrier, whereas the dynamic barriers, referred to as the conjunctival and choroidal blood flow, tear dilution, and lymphatic clearance, critically impact the bioavailability of drugs. To circumvent such barriers, the rational design of the ocular therapeutic system indeed required enriching the drug holding time and the deeper permeation of the drug, which overall improve the bioavailability of the drug in the ocular tissue. This review provides a brief insight into the structural components of the eye as well as the therapeutic challenges and current developments in the arena of the ocular therapeutic system, based on novel drug delivery systems such as nanomicelles, nanoparticles (NPs), nanosuspensions, liposomes, in situ gel, dendrimers, contact lenses, implants, and microneedles. These nanotechnology platforms generously evolved to overwhelm the troubles associated with the physiological barriers in the ocular route. The controlled-drug-formulation-based strategic approach has considerable potential to enrich drug concentration in a specific area of the eye.

Cancer has been growing nowadays consequently high number of death ascertained worldwide. The medical intervention involves chemotherapy, radiation therapy and surgical removal. This conventional technique lacking targeting potential and harm the normal cells. In drug treatment regimen, the combination therapy is preferred than single drug treatment module due to higher internalization of chemotherapeutics in the cancer cells both by enhance permeation retention effect and by direct cell apoptosis. The cancer therapeutics involves different methodologies of delivering active moiety to the target site. The active and passive transport mode of chemotherapeutic targeting utilizes advance nanocarriers. The nanotechnological strategic treatment applying advance nanocarrier greatly helps in mitigating the cancer prevalence. The nanocarrier-incorporating nanodrug directed for specific area appealed scientist across the globe and issues to be addressed in this regard. Therefore, various techniques and approaches invented to meet the objectives. With the advances in nanomedicine and drug delivery, this review briefly focused on various modes of nanodrug delivery including nanoparticles, liposomes, dendrimer, quantum dots, carbon nanotubes, metallic nanoparticles, nanolipid carrier (NLC), gold nanoshell, nanosize cantilevers and nanowire that looks promising and generates a novel horizon in cancer therapeutics.

Nanoparticles (NPs) in contact with a biological medium are rapidly comprehended by a number of protein molecules resulting in the formation of an NP–protein complex called protein corona (PC). The cell sees the protein-coated NPs as the synthetic identity is masked by protein surfacing. The PC formation ultimately has a substantial impact on various biological processes including drug release, drug targeting, cell recognition, biodistribution, cellular uptake, and therapeutic efficacy. Further, the composition of PC is largely influenced by the physico-chemical properties of NPs viz. the size, shape, surface charge, and surface chemistry in the biological milieu. However, the change in the biological responses of the new substrate depends on the quantity of protein access by the NPs. The PC-layered NPs act as new biological entities and are recognized as different targeting agents for the receptor-mediated ingress of therapeutics in the biological cells. The corona-enveloped NPs have both pros and cons in the biological system. The review provides a brief insight into the impact of biomolecules on nanomaterials carrying cargos and their ultimate fate in the biological milieu.

Cancer is among the most dreadful fatal diseases globally, and the efficacy of recent chemotherapeutic approaches is limited due to many related drawbacks. The major limitation associated with cancer chemotherapy is the poor aqueous solubility of most of the anticancer drugs, development of multidrug resistance, low bioavailability, small plasma half-life, and serious side effects to healthy tissues due to unspecific distribution of chemotherapeutic drugs. Advancement in nanoscience provides the means of specific and selective targeting of cancer cells. Chitosan, one of the naturally occurring biocompatible and mucoadhesive biopolymers that have been widely used in recent years for the effective delivery of anti-cancer drugs at the target site. Chitosan nanoparticles can encapsulate both hydrophilic and lipophilic chemotherapeutic drugs, proteins/peptides as well as different genetic materials like DNA, miRNA, siRNA, etc. in their polymeric matrix. Due to the unique polymeric matrix, these nanoparticles improve the solubility as well as the stability of encapsulated molecules in the biological system. Chitosan nanoparticles can improve the pharmacokinetic profile as well as the therapeutic efficacy of encapsulated drugs by controlling the release rates and targeted delivery process. These nanoparticles selectively deliver the encapsulated drugs to desired sites through passive or active targeting mechanisms thereby decrease the undesirable side-effects. The surface of chitosan nanoparticles can be modified with different ligands like antibodies, proteins, peptides, polysaccharides, and nucleic acids to achieve selective targeting. This review will provide a state-of-the-art perspective on recent development in chitosan-nanoparticles for smart anti-cancer therapeutic delivery. Graphical Abstract

Cancer is a progressive disease of multi-factorial origin that has risen worldwide, probably due to changes in lifestyle, food intake, and environmental changes as some of the reasons. Skin cancer can be classified into melanomas from melanocytes and nonmelanoma skin cancer (NMSC) from the epidermally-derived cell. Together it constitutes about 95% of skin cancer. Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (CSCC) are creditworthy of 99% of NMSC due to the limited accessibility of conventional formulations in skin cancer cells of having multiple obstacles in treatment reply to this therapeutic regime. Despite this, it often encounters erratic bioavailability and absorption to the target. Nanoparticles developed through nanotechnology platforms could be the better topical skin cancer therapy option. To improve the topical delivery, the nano-sized delivery system is appropriate as it fuses with the cutaneous layer and fluidized membrane; thus, the deeper penetration of therapeutics could be possible to reach the target spot. This review briefly outlooks the various nanoparticle preparations, i.e., liposomes, niosomes, ethosomes, transferosomes, transethosomes, nanoemulsions, and nanoparticles technologies tested into skin cancer and impede their progress tend to concentrate in the skin layers. Nanocarriers have proved that they can considerably boost medication bioavailability, lowering the frequency of dosage and reducing the toxicity associated with high doses of the medication.