Screening the Degradation of Polymer Microparticles on a Chip

Abstract

Enzymatic degradation of polymers has advantages over standard degradation methods, such as soil burial and weathering, which are time-consuming and cannot provide time-resolved observations. We have developed a microfluidic device to study the degradation of single microparticles. The enzymatic degradation of poly (1,4-butylene adipate-co-terephthalate) (PBAT) microparticles was studied using Novozym 51032 cutinase. PBAT microparticles were prepared via an oil-in-water emulsion solvent removal method, and their morphology and chemical composition were characterized. Then, microparticles with varying diameters of 30−60 μm were loaded into the microfluidic chip. Enzyme solutions at different concentrations were introduced to the device, and changes in the size and transparency of PBAT microparticles were observed over time. The physicochemical properties of degraded products were analyzed by FT-IR, NMR, mass spectrometry, and differential scanning calorimetry. The degradation process was also performed in bulk, and the results were compared to those of the microfluidic method. Our analysis confirms that the degradation process in both bulk and microfluidic methods was similar. In both cases, degradation takes place on aliphatic and soft segments of PBAT. Our findings serve as a proof of concept for a microfluidic method for easy and time-resolved degradation analysis, with degradation results comparable to those of conventional bulk methods.

Mechanism and kinetics of enzymatic degradation of polyester microparticles using a shrinking particle–shrinking core model

“…The methods used for loading microchannels and running the experiments are briefly discussed in supporting information per our previous study. 4 Additionally, the supporting information contains a summary of SPM-SCM model, associated RDSs, and typical conversion-time graphs are provided in Table S1 and Fig. S1, † respectively.…”

“…These particles, upon enzymatic degradation, do not experience shrinkage, rather, their appearance transforms from opaque to transparent. 4 The size of the unreacted core shrinks as the degradation proceeds which makes this polymer a suitable candidate on which to apply the shrinking-core model.…”

“…Furthermore, agitation can adversely affect degradation kinetics by lowering, or completely obscuring, autocatalytic effects. 3 Also, physiological phenomena associated with enzymatic degradation of polymers in nature are known to be slow processes, 4 therefore, static or slow agitation conditions have been suggested to study the enzymatic degradation of such polyesters. 5 Microfluidic techniques have been used to study polymer degradation on the microscale providing a slow or close-tostatic flow of enzyme solution over the substrate.…”

“…Previously, we developed a microfluidic device to qualitatively study the enzymatic degradation of a single poly (butylene adipate-co-terephthalate) (PBAT) microparticle. 4 Here we use a similar technique by designing a microfluidic device to study the degradation kinetics of a group of polymer microparticles. Because the associated transport phenomena in a continuous flow system is substantially different, kinetic models developed for bulk systems with agitation cannot be used.…”

Amine Switchable Hydrophilic Solvent Vortex-Assisted Homogeneous Liquid–Liquid Microextraction and GC-MS for the Enrichment and Determination of 2, 6-DIPA Additive in Biodegradable Film

“…Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable aliphatic-aromatic polyester belonging to petrochemical-based biodegradable plastics. It exhibits good flexibility, elongation at break, high toughness, and heat resistance, along with excellent biodegradability [1]. PBAT is recognized as a sustainable material in the generation of "green material", considered a promising alternative to traditional film materials, and has been widely used in the production of biodegradable agricultural mulching film [2,3].…”