| Background: Biodegradable thermosensitive hydrogel scaffolds
based on novel three-block PCL-PEG-PCL and penta block PNIPAAmPCL-PEG-PCL-PNIPAAm copolymers blended with gelatin were
prepared and examined on functional behavior of chondrocytes.
Methods: In this work, we compared two different thermosensitive
hydrogel scaffolds (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin and
(PCL-PEG-PCL)/Gelatin prepared by TIPS (thermally induced phase
separation) method. The feature of copolymers was characterized
by FT-IR, 1H NMR. The lower critical solution temperatures (LCSTs)
of aqueous solutions of copolymers were measured by cloud point
(turbidity) measurements. We also examined water absorption
capacity and swelling ratio. Mechanical features of the prepared
hydrogels were evaluated by stress-strain measurements. Thereafter,
isolated chondrocytes were cultured on each scaffold for a period
of 10 days and cell arrangement and morphology studied pre-and
post-plating. Cell survival assay was done by using MTT assay. The
transcription level of genes Sox-9, Collagen-II, COMP, MMP-13 and
oligomeric matrix protein was monitored by real-time PCR assay. The
samples were also stained by Toluidine blue method to monitor the
synthesis of proteoglycan. Results: Data demonstrated an increased
survival rate in cells coated seeded on scaffolds, especially (PNIPAAmPCL-PEG-PCL-PNIPAAm)/Gelatin as compared to control cells on
the plastic surface. (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin had
potential to increase the expression of genes Sox-6, Collagen-II, COMP
and after 10 days in vitro. Conclusion: Thermosensitive PCEC/Gel and
(PNIPAAm-PCEC-PNIPAAm)/Gel hydrogel scaffolds that fabricated by
TIPS method possesses useful hydrophilic properties for growth and
cell embedding and secretion of extracellular matrix. It can serve as
an ideal strategy to promote the formation of cartilage tissue. |