Amelioration of breast cancer therapies through normalization of tumor vessels and microenvironment: paradigm shift to improve drug perfusion and nanocarrier permeation.

Breast cancer (BC) is the most commonly diagnosed cancer among women. Chemo-, immune- and photothermal therapies are employed to manage BC. However, the tumor microenvironment (TME) prevents free drugs and nanocarriers (NCs) from entering the tumor premises. Formulation scientists rely on enhanced permeation and retention (EPR) to extravasate NCs in the TME. However, recent research has demonstrated the inconsistent nature of EPR among different patients and tumor types. In addition, angiogenesis, high intra-tumor fluid pressure, desmoplasia, and high cell and extracellular matrix density resist the accumulation of NCs in the TME. In this review, we discuss TME normalization as an approach to improve the penetration of drugs and NCSs in the tumor premises. Strategies such as normalization of tumor vessels, reversal of hypoxia, alleviation of high intra-tumor pressure, and infiltration of lymphocytes for the reversal of therapy failure have been discussed in this manuscript. Strategies to promote the infiltration of anticancer immune cells in the TME after vascular normalization have been discussed. Studies strategizing time points to administer TME-normalizing agents are highlighted. Mechanistic pathways controlling the angiogenesis and normalization processes are discussed along with the studies. This review will provide greater tumor-targeting insights to the formulation scientists.

Sulfo-butyl ether ß-cyclodextrin inclusion complexes of bosutinib: in silico, in vitro and in vivo evaluation in attenuating the fast-fed variability.

Bosutinib (BOS) is a BCS class IV drug that shows low oral bioavailability and high fast-fed variability. Various pharmaceutical formulations have been explored thus far in order to improve its bioavailability while avoiding fast-fed variability. In the present study, we explored cyclodextrin (CD) complexation strategy to overcome the aforementioned disadvantages associated with BOS. CD complexation is a simple, versatile and economic approach that enables formation of inclusion complexes, thereby improving aqueous solubility while nullifying pH-dependent solubility and fast-fed variability for poorly soluble drugs. Initially, we performed molecular dynamics and docking studies to select appropriate CD derivative. The results of in silico studies revealed that sulfo-butyl ether ß-cyclodextrin (SBE-CD) offered superior binding affinity with BOS. Further, Job's plot revealed that 1:1 stoichiometry of BOS and CD resulted in enhancement of BOS solubility up to ~ 132.6-folds. In vitro release studies in bio-relevant media (fasted and fed state simulated gastric and intestinal fluids) revealed higher drug release while overcoming its pH-dependent solubility. In vitro studies on K562 cells demonstrated a 1.83-fold enhancement in cytotoxicity due to enhanced ROS production and G2/M phase arrest.In vivo pharmacokinetic studies in Sprague-Dawley rats revealed insignificant fast-fed variability with AUCfast/fed 0.9493 and Cmaxfast/fed 0.8291 being closer to 1 in comparison with BOS. Hence, we conclude that SBE-CD complexation could be a promising approach in diminishing fast-fed variability of BOS.

Quality by design endorsed fabrication of Ibrutinib-loaded human serum albumin nanoparticles for the management of leukemia.

Ibrutinib (IB), a BCS class II drug suffers from limited aqueous solubility, short half-life and extensive first-pass metabolism. In this project, we aim to recruit the desirable properties of human serum albumin (HSA) as a biocompatible drug carrier to circumvent nanoparticle-associated drawbacks. Quality by design and multivariate analysis was used for the optimization of IB-NPs. Cell culture studies performed on the K562 cell line revealed that the Ibrutinib-loaded HSA NPs demonstrated improved cytotoxicity, drug uptake, and reactive oxygen species generation in the leukemic K562 cells. Cell cycle analysis revealed G2/M phase retention of the leukemia cells. In vitro protein corona and hemolysis studies revealed superior hematological stability compared to the free drug which showed greater than 40 % hemolysis. In vitro drug release studies showed prolonged release profile till 48 h. Pharmacokinetic studies demonstrated a 2.31-fold increase in AUC and an increase in half-life from 0.43 h to 2.887 h with a tremendous reduction in clearance and elimination rate indicating prolonged systemic circulation which is desirable in leukemia. Hence, we conclude that IB-loaded albumin nanoparticles could be a promising approach for the management of leukemia.

Tumor-promoting aftermath post-chemotherapy: A focus on breast cancer.

Chemotherapy is an important tool for the management of solid tumors including breast cancers (BC). Its neo-adjuvant and adjuvant use is important for shrinking tumor size and neutralizing the disseminated cancer cells. Initial chemotherapy administration often leads to a reduction in tumor size and pathological complete response. However, chemotherapy-induced tumor-free survival is not durable in BC patients. Chemotherapy is the prominent treatment for the management of triple-negative BC (TNBC), the most aggressive subtype of the BC. Various factors such as the emergence of multidrug resistance (MDR), the appearance of dormant and tolerant clones, and remodeling of the tumor microenvironment (TME) in response to chemotherapy-induced stress are responsible for tumor relapse. In current review, the authors have highlighted various cytokines and growth factors, and underlying signaling pathways such as NF-κB and PI3k/AkT, responsible for the emergence of chemo-resistance and metastasis in the TME. The present review potentially explores the role of epithelial-mesenchymal transition (EMT) in eliciting metastasis and providing stem-like phenotypes to the BC cells. The appearance of drug-tolerant sub-populations such as persister cells and BC stem cells has been discussed with mechanistic pathways. Through the current review, authors have significantly explained the mechanistic pathways of the chemotherapy-induced transformation of the tumor microenvironment (TME) constituents responsible for tumor progression. Potential therapeutic targets have been highlighted.