Enzyme-responsive smart nanocarriers for targeted chemotherapy: an overview.

Nanocarriers play pivotal roles in the field of biomedical applications, particularly in anticancer therapy. One of the prominent strategies for the transport of anticancer drugs with site-specific release and improved therapeutic efficacy is the use of an enzyme-responsive drug delivery system. There is an emerging class of cancer therapeutics engineered to control the release of a drug via enzymatic degradation. Enzymes, being an essential component of bio-nanotechnology toolbox, hold exceptional biorecognition abilities as well as outstanding catalytic properties. Often, abnormal enzyme expression observed in cancer offers many opportunities in designing nanocarriers modified with enzyme-labile linkage. Through altered physical or chemical characteristics of these nanocarriers or cleavage of the drug in response to the bio-action of enzyme, an on-demand drug release can be obtained. In this review, several classes of enzymes performing critical roles in cancer such as hydrolases, lipases, and oxidoreductases are summarized. Insights on various approaches that interfere with the mechanism of these enzymes have also been included. Finally, various smart nanocarriers such as mesoporous silica nanoparticles, gold nanoparticles, carbon-nanotubes, micelles, liposomes, and dendrimers serving as excellent platforms for enzyme-responsive formulations have been discussed.

Current trends in theranostics for rheumatoid arthritis.

The very complexity of Rheumatoid Arthritis (RA) makes its prognosis and management challenging. The manifestations pertaining to RA emerge in the late stage of the disease when the damage to bone and cartilage has already occurred. Therefore early diagnosis of RA becomes critical in order to avoid further complications and disabilities. In such a scenario, theranostics can be an ideal solution to tackle the barriers to disease management in RA patients. Nanotechnology has paved the way for emerging theranostics to achieve better targetability and high performance. The shortcomings of current diagnostic techniques and pharmacological treatment are addressed in this review. The article also summarizes the laboratory studies that have reported promising theranostic entities for RA diagnosis, treatment and discusses the outcomes of each. Novel platforms combined with newer techniques have found application in the theranostics of RA. These platforms include gold nanorods, nanoshells, nanowhiskers, magnetic nanoparticles, solid and mesoporous silica nanoparticles, etc. Photodynamic, chemo-photo responsive, magnetic field based imaging and simultaneous stimulation have been reported for the release of therapeutic moieties from these nanoplatform. Theranostics can also assist clinicians in determining the respondents and non-respondents to biological response modifiers and other treatments available for RA. This not only plays an important role in selecting the suitable therapy for every patient but also in monitoring the progress of treatment in the patient. The advantages of theranostics over current diagnosis and treatment for RA are tremendous. Hence it holds great opportunities for progress and enhancement of RA disease management.

Recent therapeutic strategies targeting beta amyloid and tauopathies in Alzheimer's disease.

Alzheimer's disease (AD) has been a global concern for years due to its severe implications that affects the quality of life of the patients. The available line of therapy for treating Alzheimer's includes acetylcholinesterase inhibitors, NMDA(N-methyl-D-aspartate) antagonists and their combination which gives only symptomatic relief rather than treating the root cause of AD. Senile plaques and neurofibrillary tangles are the characteristic features underlying Alzheimer's pathology. Several attempts have been made towards exploring the niceties of these hallmarks and targeting various aspects of amyloid and tau pathology at different stages to eliminate the ultimate cause. Approaches targeting cleavage and formation of toxic amyloid fragments by secretases, aggregation of amyloid monofilaments, and immunotherapy against amyloid deposits has been extensively studied to treat amyloid pathology. Similarly, for tau pathology, tau hyperphosphorylation, microtubule stabilization, anti-tau immunotherapy has been explored. This article focuses on AD pathology and current pharmacotherapy, precisely for amyloid and tau. Furthermore, preclinical and clinical studies along with potential leads discovered under these approaches have also been included in this article. However, despite extensive research in drug development, overcoming clinical barrier still remain a major challenge for Alzheimer's pharmacotherapy.