Current Drug Targets - Volume 23, Issue 10, 2022

Recent discoveries have unfolded many powerful emerging applications in the field of drug delivery science. For the past few years, ultrasound mediated microbubble contrast agents have been an emerging modality for diagnostic and drug delivery applications. Microbubbles are small spherical bubbles composed of a gas core encapsulated by a shell with different materials. The composition of the microbubble determines its stiffness, encapsulation efficiency, stability, and clearance from the system. A gas-filled microbubble, when activated by an acoustic pulse, can produce large volumetric oscillations and, once administered intravenously, can act as a cavitating nuclei, allowing for a wide range of ultrasound-assisted drug delivery applications. Microbubbles offer a fantastic approach to ultrasound triggered drug delivery with various drug loading techniques and targeting strategies for the uptake of bioactive substances such as polynucleotides, proteins, genes, and small-molecule drugs. Microbubbles can be used for several diagnostic and therapeutic purposes for accurate detection and treatment of various life-threatening diseases.

Alzheimer's disease (AD) is a multifactorial, progressive, neurodegenerative disorder, manifested by the loss of memory and cognitive abilities, behavioral disturbance and progressive impairment of activities of daily life. The sharp rise in the number of AD patients has brought it within the top eight health issues in the world. It is associated with the distribution of misfolded aggregates of protein within the brain. However, Alois Alzheimer initially mentioned that the reduction in brain volume in AD might be associated with the “deposition of a special substance in the cortex”. The resulting plaque found in extracellular space in the AD brain and hippocampus region, known as senile plaques, is the characteristic feature underlying Alzheimer’s pathology, where the role of amyloid- β (Aβ) peptide formation from proteolytic cleavage of amyloid precursor protein (APP) by secretase enzyme is eminent. Therefore, this review has highlighted the molecular pathophysiology of AD with a variety of available diagnostic and treatment strategies for the management of the disease, with a focus on the advancement toward clinical research to provide new effective and safe tool in the diagnosis, treatment or management of AD.

Background: In the clinical setting, anticancer therapy is routinely administered to stimulate programmed cell death or “apoptosis.” The goal is to eliminate tumor cells. Whether selective activation of apoptosis facilitates aggressive disease relapse in the longer term is still unaddressed. Apoptosis defects have a crucial role in cancer progression and carcinogenesis. Thus, targeting apoptosis may be important in developing new cancer therapeutic modalities. Methods: We summarize the shift in thinking that, while apoptosis is a barrier to oncogenesis, it paradoxically drives cancer formation and progression when executed incompletely, i.e., sublethal apoptosis. Also, we review apoptotic mechanisms, the role of apoptosis in carcinogenesis, and how it contributes to cancer treatment. Result and Conclusion: Most current research focuses on the extent of cell death in vitro, but no evidence exists that protein regulation of cell death in vitro is similar to what happens in vivo. Future research requires identifying targets upstream and downstream of such proteins through identifying protein-protein interactions in different survival/apoptosis pathways. Finding nexuses where such pathways interconnect is critical, along with possible mechanisms for regulation.

Heat shock protein (Hsp) 90 is an ATP-dependent chaperone and plays a vital role in the folding, maturation, and stability of a protein. Hsp90 and its client proteins have become targets of various diseases through the regulation of disease-related proteins. Inhibition of Hsp90 production and activity prevents ATP hydrolysis, resulting in the ubiquitination and proteasome degradation of client proteins. However, the Hsp90 inhibitor has obvious toxic side effects and the inevitable heat shock response. Cell division cycle 37 (Cdc37) is a crucial Hsp90 kinase-specific co-chaperone, which forms a complex with Hsp90 to regulate kinase and non-kinase client’s activities, cell communication, and signal transduction. The Hsp90-Cdc37 complex maintains cell survival by stabilizing abnormal client proteins and regulating cell growth signals. The abnormal activation of Hsp90-Cdc37 protein-protein interaction (PPI) often leads to the aggravation of diseases, such as cancer and neurodegenerative diseases. Compared with ATP competitive Hsp90 inhibitors, blocking Hsp90-Cdc37 PPI has higher selectivity, fewer toxic side effects, and better application prospects. This review detailed the biological characteristics of Hsp90-Cdc37 PPI and its role in several human diseases. Besides, the latest research progress in inhibitors is summarized and discussed to guide further research and clinical application.