Microneedles from fish scale biopolymer

Abstract

This paper reports on microneedles produced from biopolymer films extracted from fish scales of tilapia (Oreochromiss sp) using micromoulding technique. Evaluation of the properties of polypeptide films prepared from the fish scales gave refractive index (1.34), Protein concentration (78%), ash content (1.6%) at (22%) moisture content. The microneedles successfully inserted into artificial skin models and imaging using digital camera showed microneedles remained intact when inserted and when removed from the skin model. Microneedles also successfully inserted into porcine skin and were shown to dissolve gradually at 0s, 60s, 120s and 180s after insertion. Microneedles containing methylene blue as model drug were also produced and successfully pierced porcine skin. 3D finite element (FEM) simulations were carried out using the measured mechanical properties of the biopolymer films (Young's modulus 0.23N/mm2and tensile strength 1.8105N/mm2) to evaluate the stress distribution on various dimensions of the fish scale derived microneedles and hence, their ability to withstand force necessary to pierce the skin without fracture. Results from mechanical analysis using FEM showed that microneedles with tip radius between 10 and 100µm could withstand up to 0.12N of force per microneedle without fracture, which is indicated when the stress at the tip of the microneedle exceeds the ultimate stress of the material of fabrication. Using skin insertion tests and finite element simulations this study provides evidence that microneedles fabricated from fish scale biopolymer can effectively pierce and degrade into skin and therefore are good candidate for transdermal applications.

Microneedle characterisation: the need for universal acceptance criteria and GMP specifications when moving towards commercialisation

“…A further potential test, certainly for transparent or translucent MNs could be a refractive index test. The refractive index is a basic property of polymers which relates to their ability to bend light, it also correlates with other properties of the polymer such as electromagnetic and chemical properties [84] Understanding and developing the criteria to ensure the needles do not get plugged with human tissue will be paramount. The effective delivery of cargo is one of the tests that will more than likely be included in the standards tailored for specific MN types; however, perhaps simple geometry characterisation and OCT + TEWL would be a basic start.…”

Microneedles for drug delivery: trends and progress

“…The materials that have been used to fabricate them range from metal (Choi et al, 2013), glass, silicon (Wei-Ze et al, 2010) and biodegradable polymers (polydimethylsiloxane) (Chu & Prausnitz, 2011;Bediz et al, 2013) and silk fibroin (Tsioris et al, 2012). More recently, the use of fish scales have also been investigated (Olatunji et al, 2014). Ideally, the materials used would be pharmacologically inert, non-toxic, compatible with pharmaceutical ingredients, etc.…”

Potential of combined ultrasound and microneedles for enhanced transdermal drug permeation: A review

“…A novel dissolving MNs introduced silk fibroin as the base of the MNs because it is rigid in structure, friendly to donor permeates and dissolving very quickly [120]. More recently, biopolymers have been used in the fabrications of dissolving microneedles because they can reduce the cost of material and also increase the biocompatibility of the products [121].…”