This article published yesterday emphasized the urgent need for a targeted drug therapy such as PDC for among others metastatic breast cancer due to multidrug resistance, Thus far a combination of anticancer drugs has been used as standard chemotherapy treatment although this approach has been showing success for early stages of cancers eventually the chemotherapeutic agents flow out of the cancer cells and patient develop multi drug resistance to common anti-cancer drugs. Also chemotherapy mostly involves use of hydrophobic drugs that can be rapidly cleared from the tumor site due to their small molecular weight. This can result in lower circulation half-life and sub-therapeutic concentrations at the tumor site. To remedy the problem to certain extent a targeted anticancer drug delivery into cancer cells could result in higher dosage of the agent thus mitigate the multidrug resistance issue.
“Advanced breast cancer, which has metastasized to various organs, may not completely be curable with currently available chemotherapeutics. The last decade has seen a rise of targeted therapies for advanced or metastatic breast cancer considering the heterogeneity of the disease. An elevated efflux of chemotherapeutic drugs from the cancer cells leads to lower drug accumulation. This is the leading cause of drug resistance to chemotherapeutic drugs. Drug efflux transporters, also called efflux pumps, are mainly responsible for the development of multidrug resistance (MDR) in cancer cells. Targeted drug delivery for avascular tumor cells, such as metastatic breast cancer, pancreatic, and prostate cancers, is challenging. Actively targeted nanocarrier systems utilize certain receptors that are overexpressed on cancer cells compared to normal cells for selective delivery of chemotherapeutic agents to the cancer cells. Actively-targeted nanocarriers can accommodate antibodies, peptides, polymers, DNA aptamers, and small molecules for selective detection and uptake into the cancer cells.
Although, monoclonal antibodies can be a good tool for tumor-targeting, their large size can possess a formulation hurdle and alter NPs pharmacokinetic and pharmacodynamics properties. An equally effective alternative for antibody targeting can be the use of peptides.
Despite many recent discoveries on therapeutic interventions, cancer chemotherapy represents the most common treatment modalities for the disease. Successful treatment modalities impose three to four drugs at once. Patients in early stage of cancer respond, but due to MDR, cancer cells adapt treatment resistance and cause a relapse by overpowering therapy. As a result of high and complex dosing regimens with multiple drugs, high toxicity is caused and many treatments fail. Hopefully, current trends on targeted nano-therapeutics may overcome some of these inadequacies and advent successful breast cancer therapy.”
https://www.mdpi.com/1422-0067/22/9/4673