Synthesis and Self‐Assembly of Amphiphilic Block Copolymers from Biobased Hydroxypropyl Methyl Cellulose and Poly(l‐lactide)

Abstract

A series of well‐defined hydroxypropyl methyl cellulose‐block‐poly(l‐lactide) (HPMC‐b‐PLLA) diblock copolymers are synthesized via UV‐initiated thiol‐ene click reaction of thiol‐terminated HPMC with different block lengths and allyl‐terminated PLLA, using 2,2‐dimethoxy‐2‐phenylacetophenone as photocatalyst. The former is obtained by coupling the reducing aldehyde endgroup of short chain HPMC with the amine group of cysteamine, and the latter by ring‐opening polymerization of l‐lactide in the presence of allyl alcohol. Fourier transform infrared (FT‐IR), nuclear magnetic resonance (1H NMR), and diffusion ordered spectroscopy NMR confirm the successful coupling of both blocks. The molar mass of the resulting copolymers ranges from 7000 to 12 800 g mol−1 as determined by size exclusion chromatography. The copolymers are able to self‐assemble in aqueous medium, yielding micelles of 50–100 nm with core–shell structure as evidenced by dynamic light scattering, transmission electron microscopy, and 1H NMR. The critical micelle concentration of copolymers ranges from 0.12 to 0.15 mg mL−1. Last but not the least, the copolymers exhibit thermoresponsive behavior with a lower critical solution temperature around 80 °C.

Surface Modification of PTLG Terpolymer Using PNIPAAm and Its Cell Adhesion/Detachment Behavior

“…Modifying biomaterials surface toward stimuli-sensitive functionalization for medical implant is a feasible way to simultaneously improve the biocompatibility and hydrophilicity. [6,7] Poly(Nisopropylacrylamide) (PNIPAAm) has been well known as a thermoresponsive polymer which exhibits a lower critical solution temperature (LCST) at 32 °C. It has been investigated in various biomedical applications such as drug controlled release, cell culture, injectable carrier, tissue engineering, etc.…”

Saccharide‐based nanocarriers for targeted therapeutic and diagnostic applications

“…). ‘Grafting from’ methods include free radical polymerization (ceric ion initiation, the use of Fenton's reagent, γ ‐radiation, thermal initiation and photolysis), controlled/living radical polymerization and ring‐opening polymerization …”

“…'Grafting from' methods include free radical polymerization (ceric ion initiation, 22 the use of Fenton's reagent, 23 308 www.soci.org V Mukwaya, C Wang, H Dou -radiation, thermal initiation and photolysis), 24 controlled/living radical polymerization 25 and ring-opening polymerization. 26 Despite the fact that block copolymers have the ability to form an array of nanoscale ordered structures, graft copolymers remain popular especially in the synthesis of polysaccharide-containing polymers. Graft copolymers have two main advantages that make them desirable for the fabrication of nanocarriers.…”

PLLA‐Grafted Gelatin Amphiphilic Copolymer and Its Self‐Assembled Nano Carrier for Anticancer Drug Delivery

“…Poly( l ‐lactide) (PLLA), a synthetic polyester, presents outstanding biocompatibility, biodegradability, nontoxicity, and good mechanical properties . PLLA is obtained from L‐lactic acid which is primarily derived from corn starch .…”