Bio-functional inorganic materials: an attractive branch of gene-based nano-medicine delivery for 21st century.

Treatment of a physiological disorder in the genetic level (gene therapy) and induction of a specific immunity by means of a genetic material (genetic vaccination), are considered two revolutionary approaches for clinical medicine. The implementation strategies for these basic concepts demand a vehicle for nucleic acid delivery. Viral delivery systems, although highly efficient, possess severe limitations in terms of life safety and thus non-viral synthetic systems have become increasingly desirable. Intensive efforts for the last 3 decades enabled the development of a lot of synthetic devices, most of which belong to cationic lipids, peptides and other polymers, but comparatively little attention was paid to inorganic materials. This is the first article aimed at reviewing the dramatic progress of non-viral gene delivery research focusing on the functional inorganic materials. Both biodegradable and non-biodegradable inorganic particles have been fabricated in the nano-scale with the attributes of binding DNA, internalizing across the plasma membrane and finally releasing it in the cytoplasm for final expression of a protein. Some in vivo trials also brought highly satisfactory results demonstrating their potential applications in the clinical medicine.