Multifunctional nanocrystals for cancer therapy: a potential nanocarrier

Abstract

Nanotechnology-based drug delivery systems offer an unprecedented opportunity for tumor targeting. Nanocrystals are carrier-free crystalline nanosized solid drug particles. Due to high drug loading (as high as 100%), and being free of organic solvents or surfactants or polymers or solubilizing chemicals, nanocrystals have attracted great attention in the field of drug delivery for treatment of various cancers. Additionally, the hybrid or multifunctional nanocrystal has been extensively investigated for applications in experimental as well as clinical settings to improve delivery efficiency of therapeutic and diagnostic agents. This review gives an overview of recent advances and current status of nanocrystals, especially with respect to the method of preparations, physicochemical characterizations, in vitro/in vivo performance, scale-up techniques and applications in the field of drug delivery for different tumor targeting. Recently much attention has been given to multifunctional nanocrystals showing the capability to codeliver multiple components that target the drug delivery by surface functionalization, performing therapy as well as diagnosis. Preparative techniques like high-pressure homogenization, precipitation, and media milling have been known to show large-scale production of nanocrystals. High therapeutic applications of nanoparticles enable its administration through various routes like oral, parenteral, pulmonary, dermal, and ocular. Along with preparation and characterization, this review will dwell on the progress involved with multifunctional nanocrystals for cancer therapy and theranostics. Most available results in multifunctional nanocrystal targeting rely upon in vitro and animal models, which do not match the actual environment of the tumor in the body, which is one of the major obstacles. Other challenges faced when it comes to nanocrystals are scale-up and reproducibility. In addition, potential problems and possible future research directions for the advancement of newer techniques of multifunctional nanocrystals that make them highly suitable for tumor targeted are highlighted in this review