Biodegradable medical device is another trend of developing implantable medical devices. The biodegradable medical devices have specific properties of biocompatibility and biodegradability. Once the in vivo function of the device completed, the device will degrade and disappear, which could avoid additional surgery to benefit patients, physically and economically. Although the biodegradable devices increase the acceptance of implantable medical devices by patients, the energy supply method is still a problem and highly required.
From 2014, we started to investigate the energy supply part of controlled biodegradable nano medical devices. By developing biodegradable nanogenerators (BDNGs) with charge separation and electric potential generation, the BDNGs have the ability of collecting and converting mechanical energy in the body. We also achieved in vitro directional growth of neuron cells successfully, as a demonstration of nerve repair, which was orientated by electric field generated by BDNGs. This work was published in Science Advances (Sci. Adv. 2016, 2: e1501478).
These works are concentrated on controlled biodegradable nano medical devices and biosensors, for curing injures, repairing tissues, detecting diseases, sensing and monitoring physiological functions. The degradation time of the device can be controlled after implantation. This device will realize one-stop healthcare and no residue after treatment.
2016年，我们在Science的子刊Science Advances发表论文（Sci. Adv. 2016; 2 : e1501478），介绍了一种具有电荷分离与驱动能力的生物降解纳米发电机（Biodegradable nanogenerator，BDNG）可在体内产生电能，并成为全可降解的纳米医疗电子器件的能源部分。我们验证了基于BDNG的纳米医疗器件可以控制细胞定向生长和排列，并具有促进神经修复的能力，这对植入式可降解医疗器件的研发具有重要意义，未来的应用前景非常广阔
Self-powered implantable medical devices based on nanogenerators
Miniaturization is one of the trends in developing new implantable medical devices. It is extremely difficult to deal with the ambivalence in miniaturization, between the long-term energy supply and growth of energy consumption caused by multi-functionalization. Nanogenerators are prone to be the key of dealing with the in vivo energy supply of implantable medical devices.