Synthesis of uniform submicron poly(lactic acid)-based particles/capsules by radical precipitation polymerization

Chayanan Khotchana; Pongsathon Phapugrangkul; Pakorn Opaprakasit; Dolnapa Kaewpa; Preeyaporn Chaiyasat; Amorn Chaiyasat

doi:10.1016/j.colsurfb.2021.112122

Synthesis of uniform submicron poly(lactic acid)-based particles/capsules by radical precipitation polymerization

Colloids Surf B Biointerfaces. 2021 Dec:208:112122. doi: 10.1016/j.colsurfb.2021.112122. Epub 2021 Sep 21.

Authors

Chayanan Khotchana¹, Pongsathon Phapugrangkul², Pakorn Opaprakasit³, Dolnapa Kaewpa⁴, Preeyaporn Chaiyasat⁵, Amorn Chaiyasat⁶

Affiliations

¹ Department of Chemistry, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand.
² Biodiversity Research Center, Thailand Institute of Scientific and Technological Research (TISTR), Pathum Thani 12120, Thailand.
³ School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology (SIIT), Thammasat University, Pathum Thani 12121, Thailand.
⁴ Division of Biology, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand.
⁵ Department of Chemistry, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand; Advanced Materials Design and Development (AMDD) Research Unit, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand.
⁶ Department of Chemistry, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand; Advanced Materials Design and Development (AMDD) Research Unit, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110, Thailand. Electronic address: a_chaiyasat@mail.rmutt.ac.th.

PMID: 34592673
DOI: 10.1016/j.colsurfb.2021.112122

Abstract

Poly(l-lactic acid) (PLLA) is a well-known biopolymer, usually synthesized via step-growth or ring-opening polymerization from lactic acid or a lactide monomer, respectively. PLLA microspherical particles are produced by dispersion polymerization with a ring-opening lactide monomer using a particular copolymer chain as a stabilizer. This is not easy to achieve when dehydration is needed. Here, a robust and simple synthesis of a nearly monodisperse, submicron PLLA-based particle/capsule was proposed via radical precipitation polymerization without the use of surfactant. A commercial PLLA was first glycolyzed with ethylene glycol to obtain a low molecular weight glycolyzed PLLA (GPLLA). Then, the GPLLA was copolymerized with methacrylic acid and ethylene glycol dimethacrylate monomers using a benzoyl peroxide initiator. Active sites on the GPLLA backbone were generated by hydrogen abstraction of benzoyloxy radicals that further copolymerized before self-assembly to form the polymer particles. Uniform particle size of about 580 nm with a low polydispersity index (PDI) of 0.012 was obtained. This method was also implemented to produce nearly monodisperse capsules containing linalool. The particle size of PLLA-based capsules was about 280 nm with narrow particle size distribution (PDI of 0.120). The PLLA-based capsules effectively inhibited microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans and were not toxic to human cells.

Keywords: Polylactic acid; Polymer capsule; Polymer particle; Precipitation polymerization.

MeSH terms

Capsules
Humans
Polyesters*
Polymerization
Polymers*

Substances

Capsules
Polyesters
Polymers
poly(lactide)