Effects of hydroxyapatite particle size on PAH-GMA hydrogel
Venkata Damaraju Mentor: Dr. Sidney Sit What is a hydrogel? Biocompatible jello-like substance
A matrix of polymers Poly(allylamine hydrochloride) (PAH) Glycidyl methacrylate (GMA) Poly (ethylene glycol) diacrylate (PEG-DA) Uses of hydrogel Cell and tissue repair/regeneration
Drug delivery systems Wound dressing Cornea implants Problem? Cells dont stick to the hydrogel! Solution? Add adhesive peptides Add particles Particles create pores
Allow cells to filter in and self adhere Which particles? Hydroxyapatite Found in bones
Micro size (~ m) Nano size (~100 nm) Found in bones My experiment setup Negative control Experimental Group 1
Sonicated for 20 min. Both nano and micro particles Experimental Group 2 Sonicated for 40 min. Both nano and micro particles Electrochemical Impedance Spectroscopy
Non-destructive way of characterizing the physical properties Measures the impedance (Resistance) over a frequency range Constant AC current of 0.1 mA Experimental Group 1 Experimental Group 2 SEM Imaging Control hydrogel without particles SEM Images Hydrogel with hydroxyapatite particles Conclusion Addition of particles decreased the overall impedance
Lower impedance means more pores Sonication for 40 min gave better dispersion of particles SEM shows particles settled in the hydrogel, but as very small fragments Future work Perform cell culture on the hydrogel with particles
Add other particles to achieve larger pores Acknowledgement Dr. Sidney Sit Stephanie Tully Dillip Praveen Syeda
Karen Xu Nicolas McHughes