Microfabricated implants for applications in therapeutic delivery, tissue engineering, and biosensing

Abstract

By adapting microfabrication techniques originally developed in the microelectronics industry novel device for drug delivery, tissue engineering and biosensing have been engineered for in vivo use. Implant microfabrication uses a broad range of techniques including photolithography, and micromachining to create devices with features ranging from 0.1 to hundreds of microns with high aspect ratios and precise features. Microfabrication offers device feature scale that is relevant to the tissues and cells to which they are applied, as well as offering ease of en masse fabrication, small device size, and facile incorporation of integrated circuit technology. Utilizing these methods, drug delivery applications have been developed for in vivo use through many delivery routes including intravenous, oral, and transdermal. Additionally, novel microfabricated tissue engineering approaches propose therapies for the cardiovascular, orthopedic, and ocular systems, among others. Biosensing devices have been designed to detect a variety of analytes and conditions in vivo through both enzymatic-electrochemical reaction and sensor displacement through mechanical loading. Overall, the impact of microfabricated devices has had an impact over a broad range of therapies and tissues. This review addresses many of these devices and highlights their fabrication as well as discusses materials relevant to microfabrication techniques.

DNA-Based Nanotechnology Biosensors for Surgical Diagnosis

“…An ideal biosensor should not only complete its intended function (recognition and detection), but it also needs to possess other benefits (such as drug release, mechanical support, gene therapy, biocompatibility, etc.) (Ménard-Moyon et al 2010;Ainslie and Desai 2008;Wadhwa et al 2006).…”

“…A conductive polymer, like polypyrrole, can be coated on the implants and embedded with drugs. With electrical stimulation, molecular chains of polypyrrole break and can release the embedded drugs (Ainslie and Desai 2008;Wadhwa et al 2006). Notably, by controlling the electrical current in the implant, the drug release rate is adjustable.…”

Microneedles for drug delivery: trends and progress

“…(Henry et al, 1998;Park et al, 2005;Gupta et al, 2009;Swain et al, 2011;Kommareddy et al, 2013;Mansoor et al, 2013;Torrisi et al, 2013;Pierre & Rossetti, 2014). There has been a lot of research conducted on MNs for the delivery and monitoring of various drugs such as glucose control for diabetics (Ito et al, 2006;Nordquist et al, 2007;Ainslie & Desai, 2008;El-Laboudi et al, 2013;Taylor & Sahota, 2013;Ita, 2014), Alzheimer's disease (Wei-Ze et al, 2010), anticancer (Fang et al, 2008) and other conditions (Ezan, 2013). Vaccines have also been a prominent research field with numerous studies developed to allow dose sparing effects (Edens et al, 2013;Norman et al, 2014;van der Maaden et al, 2014).…”

Current Trends in MEMS Drug Delivery Techniques

“…By using different polymeric materials for making various reservoirs on the micro patches for storing different drugs, the time and rate of release of drugs can be precisely regulated as different polymeric materials have different dissolution rates and hence, we can achieve a controlled release of several drugs leading to better therapeutic effects and also preventing the wastage of drugs and reducing their side effects [28], [29].…”

“…Patterning of photolithographic polymers -SU-8 and PMMA is done using micro-molding. The availability of various polymeric materials for microfabrication provides flexibility to the designer, as the designer can design the microdevices with proper drug release kinetics, biodegradability, cell absorption and various other phenomena related to micropatches by using these materials appropriately [28], [29].…”