Preparation of thermosensitive PNIPAm-based copolymer coated cytodex 3
microcarriers for efficient non-enzymatic cell harvesting during 3D
culturing
Abstract
Enzymatic detachment of cells might damage important features of cells
and could affect subsequent function of cells in various applications.
Therefore, non-enzymatic cell detachment using thermosensitive polymer
matrix is necessary for maintaining cell quality after harvesting. In
this study, we synthesized thermosensitive PNIPAm-co-AAc-b-PS and
PNIPAm-co-AAm-b-PS copolymers and LCST was tuned near to body
temperature. Then, polymer solutions (5% w/v, 10% w/v, and 20% w/v)
were spin coated to prepare films for cell adhesion and thermal-induced
cell detachment. The apha-step analysis and SEM image of the films
suggested that the thickness of the films depends on the molecular
weight and concentration which ranged from 206 nm to 1330 nm for
PNIPAm-co-AAc-b-PS and 97.5 nm to 497 nm for PNIPAm-co-AAm-b-PS. The
contact angles of the films verified that the polymer surface was
moderately hydrophilic at 37°C. From cell attachment and detachment
studies, RAW264.7 cells, were convincingly proliferated on the films to
a confluent of >80 % within 48 days. However, relatively
more cells were grown on PNIPAm-co-AAm-b-PS (5%w/v) films and
thermal-induced cell detachment was more abundant in this formulation.
As a result, commercial cytodex 3 microcarrier was coated with
PNIPAm-co-AAm-b-PS (5%w/v) and interestingly enhanced cell detachment
with preserved potential of recovery was observed at low temperature
during 3D culturing. Thus, surface modification of microcarriers with
PNIPAm-co-AAm-b-PS could be vital strategy for non-enzymatic cell
dissociation and able to achieve adequate number of cells with maximum
cell viability, and functionality for various cell-based applications.
Keywords: surface coated microcarriers; thermosensitive polymer;
non-enzymatic cell detachment