Inkjet printing as a technique for filling of micro-wells with biocompatible polymers

Abstract

a b s t r a c tWe present an innovative technique to dispense precise amounts of polymer solutions into large arrays of microscopic wells. An inkjet printer (NP 2.1 GeSim, Germany) is used to fill micro-wells with poly (vinyl pyrrolidone) (PVP K10). The micro-wells are fabricated with cavity diameters of 300 lm down to 50 lm with SU-8 with two steps of negative photolithography. Inkjet printing is shown to be a suitable technique to dispense defined volumes of solution (down to 0.3 nL) in a highly reproducible way. The filling with polymer can be controlled varying the concentration of the solution and the number of dispensed droplets. Solutions of up to 20 wt.% PVP in water are successfully spotted.

Micro/nanofabricated platforms for oral drug delivery

“…Boisen and co-workers recently employed an inkjet printer to load a drug solution into microdevice reservoirs [121, 122], which is a quasi-no-waste performance technique as shown in Figure 4 B. They also loaded microdevice reservoirs with hydrophobic drugs in the absence of toxic organics by incorporating supercritical fluid impregnation with inkjet printing [123].…”

pH-triggered drug release from biodegradable microwells for oral drug delivery

“…A representative example of a drug-filled microwell is shown in Fig 4, clearly illustrating that the process resulted in complete filling of microwells and a negligible distribution of drug on the edge of the well. Methods utilized to date for drug filling of micro devices (i.e., microspotting and injection) have been limited to use in conjunction with aqueous drug solutions, and ideally with aqueous solutions containing 15-25 v/v% water-soluble polymer (Marizza et al 2013). The use of such filling methods and conditions is time consuming, unsuitable for poorly watersoluble drugs, and furthermore impractical for large-scale filling of micro devices (Ahmed et al 2002;Marizza et al 2013).…”

“…Methods utilized to date for drug filling of micro devices (i.e., microspotting and injection) have been limited to use in conjunction with aqueous drug solutions, and ideally with aqueous solutions containing 15-25 v/v% water-soluble polymer (Marizza et al 2013). The use of such filling methods and conditions is time consuming, unsuitable for poorly watersoluble drugs, and furthermore impractical for large-scale filling of micro devices (Ahmed et al 2002;Marizza et al 2013). In contrast, the modified screen printing technique presented here constitutes a method where drug can be filled into devices in a relatively short time period, and can also be utilized for various types of drugs and drug formulations without the requirement for water solubility.…”

Planar Bioadhesive Microdevices: A New Technology for Oral Drug Delivery

“…In one study, microdevices were brushed with a solution of sodium chloride, and surface interactions with drug solvent resulted in collection and crystallization of the model drug in the device reservoirs to provide a high-throughput method of drug loading with minimal drug waste (Figure 5B) [56]. In a more precise drug loading method, Marizza et al recently developed inkjet printing for loading of drug solutions into microdevice reservoirs (Figure 5C) [100]. While this method requires sequential loading of each microdevice in a semi-automated manner and is not currently as high-throughput as discontinuous dewetting or photolithographic drug loading techniques, it is capable of precise, quasi-zero-waste performance.…”

“…C . Inkjet printing can be utilized to deposit droplets of drug solution into device reservoirs, which later dries, leaving solidified drug [100]. D .…”