Scaffolds for Tissue Engineering Drug Delivery Systems Self healing Coating biomaterial Biosensors

1. Smart “Anti-Bacterial” Silk-Silver
Nanoparticles Hydrogel Biosynthesis
Omoyayi Ibrahim O.
PhD Biomedical Engineering (in view)
December, 2018.

2. Hydrogel
 Water- swollen polymeric materials that
maintain a distinct three-dimensional
structure.
 Due to their high water content, most hydrogel
structures posses excellent biocompatibility.
 Classification;
 Natural, Synthetic, Hybrid hydrogels
 On the basis of naure of crosslinking
 Covalent or Non-covalent (physical) gels
 Homopolymer, Copolymer, interpenetrating,
or double networks
Nanowerk, 2015

3. Impacts of Hydrogels

4. Smart Hydrogel
 Scaffolds for Tissue Engineering
 Drug Delivery Systems
 Self healing
 Coating biomaterial
 Biosensors
 Recombinant DNA
technology
 CRISPR
 TALEN
 PCR

5. Hydrogels in Pathology &
Oncology
 microRNA Detection of Diseases
 Therapeutic Hydrogels
 Hydrogels as smart drug carrier for DDS

6. Hydrogels in Pathology & Oncology
Trends in Biotechnology, November 2017, Vol. 35, No. 11 http://dx.doi.org/10.1016/j.tibtech.2017.06.015

7. Hydrogels in Pathology & Oncology
Trends in Biotechnology, November 2017, Vol. 35, No. 11 http://dx.doi.org/10.1016/j.tibtech.2017.06.015
SMART

8. Biogenesis of miRNA
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5078622
SMART
HYDROGEL

9. Research Methods
A B c D
Hydrogel Synthesis
Green Synthesis of Silver Nanoparticles (AgNPs)
Omoyayi et al., J Bioengineer & Biomedical Sci 2018, 8:3
20g of dried olive leaf was grounded immersed in 20mL Ethanol.
The solution was put in a water bath at 30oC, 100rpm for 3 days.
Filteration, Dehumification of the Olive leaf extract
AgNO3(aq) of 0.034g was added to 5ml of Olive leaf extract to fix up the solution up to 1 x
10-3M of AgNPs

10. Research Methods
Hydrogel Scaffolds Preparation
Hydrogel SF SF+ AgNPs SF + AgNPs
Cross linking Ratio 1:0 2:1 1:1
Scaffolds SFH SSN SSN*
Freeze Drying
Using the crosslinking ratio, green synthesized AgNPs were added
separately to 2.50ml aqueous silk fibroin solution for freeze-drying
scaffolding. The resulting scaffolds was labeled as thus; SFH (SF
solution), SSN (SF+ low AgNPs) and SSN* (SF+ high AgNPs).

11. Research Methods
Characterization of Hydrogels
Fourier Transmission Infrared Spectroscopy (FTIR)
DLS Particle Size Analyzer
DFC Optical Microscopy
INSTRON universal mechanical testing machine.
Antibacterial Comparison of Hydrogels – Disc diffusion test
The samples’ activity was tested against B. cereus (gram positive) and E. coli (gram negative)
Bacterial were cultured on containing the surface of nutrient - agar (typetone 1%, yeast extract
0.5%, NaCl 0.5%, agar 1%, 1000 mL of distilled water, pH 7.0)
Autoclaved under 121°C for at least 20 min.
O.D value of 0.7 was used to estimate the optimum concentration of each cells
The activity was determined by measuring the diameter of the inhibition zone in mm
Using Ciprofloxacin as the antibacterial drug

12. Research Results
Aqueous Silk Fibroin solution previously stored at 4OC was dried
at room temperature for 3 days to obtain transparent clear,
sticky, adhesive hydrogel.
Aqueous SF SFH X20mg Optical Microscopy

13. Research Results
Swelling behavior of SFH

14. Research Results

15. Research Results
AgNPs Light Scattering (DLS) Analysis

16. Research Results
Characterization of Hydrogels – Optical Images
SFH SSH SSH*
Sample Young’s Modulus, E(MPa)
SFH 10 ± 0.42
SSH 12 ± 0.21
SSH* 13 ± 0.28
Strength and Elasticity of Hydrogel

17. Research Results
F.T.I.R Structural Analysis for SFH, SSH, SSH*

18. Research Results
Antibacterial Activities of Hydrogels Against Gram Negative Bacterial

19. Research Results
Antibacterial Activities of Hydrogels Against Gram Positive Bacterial

20. Research Results
Antibacterial Activities of Hydrogels Against Gram Positive Bacterial

21. Take Home!
The antibacterial agar test results revealed that the presence of silver
nanoparticles was effective against both gram positive and gram negative
bacterial
Higher inhibition of bacterial from hydrogel of higher silver nanoparticle
concentration
The presence however seems to have more effect on the B. cereus than E.
Coli
SFH had no effect on both bacterial types
SSH* was most effective in both bacterial having a close diffusion diameter
to the drug used
The presence of silver nanoparticles in hydrogel has proven to inhibit
bacterial contamination

23. Thank you for your time 