Development of a pH indicator immobilized-gel-sheet for microenviroment analysis

Abstract

Detection of change in microenvironmental pH may be essential for analyzing biological processes, if transitory biodegradable scaffold materials are used for tissue engineering in bone regeneration. In this study, we created a pH indicator immobilized-gel-sheet for pH measurement. By using gel-sheet, we can investigate the local microenvironment of biodegradable materials, such as octacalcium phosphate (OCP), under the various protein adsorptions. The gel-sheet was made of a photocrosslinkable prepolymer solution (TUPR-5), which was easily immobilized by the method that the pH indicator is entrapped in a porous polymeric substrate. Bromothymol Blue (BTB) immobilized-gel-sheet was mounted in a biochip made of polydimethylsiloxane (PDMS) with a flow channel. The pH value was calculated by detecting the color changes, and presented as the pH distribution via a custom-made application. The pH sensing was carried out based on the surrounding color information of an OCP granule if incubated in culture medium. The gel-sheet detected the pH values of the condition around an OCP granule, showing the decrease from pH 7.8 to 8.8. As a whole, the proposed pH indicator is capable of providing pH level by high-spatial resolution.

Fabrication of Polysaccharide-Based Halochromic Nanofibers via Needle-Less Electrospinning and Their Characterization: A Study of the Leaching Effect

“…The incorporation of a halochromic dye into a desired nano-fibrous matrix could, therefore, be exploited to achieve a visual sensor [ 13 ], with the ability to detect the effects by naked eye. The pH sensitive electrospun nanofibers can find wide applications in the areas of the smart packaging of food and beverages [ 14 ], textiles [ 15 ], tissue engineering [ 15 , 16 , 17 , 18 ], water filtration, analysis of microenvironmental pH change involved in various biological processes [ 19 ], wound dressings, and microbiological studies [ 20 ]. Indeed, the nanofibrous matrix represents an ideal carrier for halochromic dyes, aiming to achieve long-lasting and fast responsivity.…”

Development of Highly pH-Sensitive Hybrid Membranes by Simultaneous Electrospinning of Amphiphilic Nanofibers Reinforced with Graphene Oxide

“…Studies have been carried out to fabricate pH-sensitive ENMs for smart beverage packaging [2], textiles [3,4], tissue engineering [5,6,7], detecting the microenvironment of various biological processes [8] and microscopic observations of microorganisms [9]. Schueren et al [10] used polyspinning to develop pH-sensitive polyamide 6.6 nanofibers for a limited range of pH values.…”