The majority of failures in prosthetic implants and devices are caused by infections. Microbial infections are one of the major causes of these failures. The present article reviews various techniques such as modification in surface chemistry/composition and tailored structures (micro to nano) for improving the antibacterial response of prosthetic implants. In addition, the application of external stimulants such as magnetic and electric fields, as well as polarization, is recently realized as a fairly appealing approach to diminish the bacterial population. A comprehensive response of surface modifications as well as external stimuli in inducing the antibacterial response in prosthetic implants has also been summarized. The mechanisms for the antibacterial response due to these modifications, such as generation of toxic metal ions by dissolution of their respective oxides, and production of reactive oxygen species (ROS), such as singlet oxygen, hydroxyl radicals (OH–), hydrogen peroxide (H2O2), superoxides, peroxides (O2 –2), etc., have been elaborately discussed.

From the point of view of biocompatibility of bone analog materials, cell-material interaction is of fundamental importance. In this article, we report the effect of pulse electric field stimulation on cell-material interaction by analyzing cellular functionality and viability. An in-house fabricated pulse electric field setup was used for the application of electric field during cell culture experiments. To optimize voltage/electric field, the first set of exploratory experiments was conducted with varying field strength at fixed frequency, and subsequently, the frequency of the electrical stimulation was varied to study its influence on the proliferation of L929 mouse fibroblast cells on gelatin-coated control disc. Subsequently, L929 cells were cultured on hydroxyapatite (HA) and HA-40 wt % BaTiO₃ composite. Cell-cultured samples were analyzed qualitatively as well as quantitatively using fluorescence microscope and scanning electron microscope. It has been demonstrated that due to the application of electric field during the cell culture experiment, the cell proliferation and the cell spreading on the surface of the biomaterials were enhanced within a narrow window of voltage/frequency of electrical stimulation. At lower field intensities, the energy density is quite low and increases parabolically with field strength. There is no significant increase in the temperature (ΔT ~10⁻⁵ K) of the medium due to the application of short duration pulse electric field. This led us to believe that electric field with appropriate strength and duration can enhance the cell-material interaction.

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The primary purpose of the present work was to illustrate whether cell proliferation can be enhanced on electroactive bioceramic composite, when the cells are cultured in the presence of external electrical stimulation. The two different aspects of the influence of electric field (E-field) application toward stimulating the growth/proliferation of bone/connective tissue cells in vitro, (a) intermittent delivery of extremely low strength pulsed electrical stimulation (0.5-4 V/cm, 400 ls DC pulse) and (b) surface charge generated by electrical poling (10 kV/cm) of hydroxyapatite (HA)-BaTiO 3 piezobiocomposite have been demonstrated. The experimental results establish that the cell growth can be enhanced using the new culture protocol of the intermittent delivery of electrical pulses within a narrow range of stimulation parameters. The optimal E-field strength for enhanced cellular response for mouse fibroblast L929 and osteogenic cells is in the range of 0.5-1 V/cm. The MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay results suggested the increased viability of E-field treated cells over 7 d in culture, implicating the positive impact of electrical pulses on proliferation behavior. The alizarin red assay results showed noticeable increase in Cadeposition on the E-field treated samples in comparison to their untreated counterparts. The negatively charged surfaces of developed piezocomposite stimulated the cell growth in a statistically noticeable manner as compared with the uncharged or positively charged surfaces of similar composition.