Title Page
Contents
List of Abbreviation 11
Abstract 12
1. Introduction 14
1.1. Skin anatomy 14
1.2. Skin wound healing 16
1.3. Requirement of wound dressings 18
1.4. Synthetic and natural polymers 19
1.5. Nanofibrous wound dressings 24
1.6. Antibacterial drug loaded scaffolds 25
2. Materials and Methods 27
2.1. Materials 27
2.2. Fabrication of composite nanofibrous mats 27
2.3. Characterization of nanofibrous scaffolds 31
2.3.1. Scanning electron microscopy (SEM) 31
2.3.2. Fourier transform infrared spectroscopy analysis (FTIR) 31
2.3.3. X-ray diffraction analysis (XRD) 31
2.3.4. Thermal properties analysis 31
2.3.5. Mechanical properties of composite scaffolds 32
2.3.6. Contact angle of scaffolds 32
2.3.7. Swelling properties of composite scaffolds 33
2.3.8. In vitro drug releasing properties 33
2.4. Biocompatibility studies of nanofibers in vitro 33
2.5. Antibacterial activity 35
2.6. In vivo wound healing model 36
2.7. Histomorphological analysis 38
2.8. Statistical analysis 39
3. Results and discussion 40
3.1. Characterization of the electrospun nanofibers 40
3.1.1. Morphological analysis 40
3.1.2. FTIR spectroscopy 41
3.1.3. X-ray diffraction analysis (XRD) 42
3.1.4. Thermal behavior analysis 46
3.1.5. Mechanical properties 47
3.1.6. Contact angle 50
3.1.7. Swelling properties 51
3.1.8. In vitro drug releasing properties 52
3.2. In-vitro cell adhesion, and proliferation 56
3.3. Antibacterial activity 60
3.4. Macroscopic analysis of wound closure 62
3.5. Histological analysis 66
4. Conclusion 68
5. Reference 69
Table 1. Requirements of an ideal wound dressing 20
Table 2. Commercially available wound dressings 21
Table 3. Fabrication parameters for the gentamicin-loaded PVA/Gel nanofibrous membranes 30
Fig. 1. Structure of the skin 15
Fig. 2. Wound healing process 17
Fig. 3. Schematic of the fabrication process of PVA/gelatin/gentamicin nanofibrous scaffolds 29
Fig. 4. In vivo ICR mouse model 37
Fig. 5. SEM micrographs at (A) 5k× and (B) 15k× magnifications and (C) corresponding nanofiber diameter distribution 43
Fig. 6. FTIR spectra of pure materials and nanofibrous scaffolds 44
Fig. 7. X-ray diffraction profile of pure materials and nanofibrous scaffolds 45
Fig. 8. Thermogravimetric analysis of pure materials and nanofibrous scaffolds 48
Fig. 9. Differential scanning calorimetry of pure materials and nanofibrous scaffolds 48
Fig. 10. Mechanical characterization of nanofibrous scaffolds: (A) typical stress-strain curve, (B) tensile strength, (C) strain reported at maximum load, and (D) strain at break. 49
Fig. 11. (A) Representative images and the (B) Dynamic water contact angle of fabricated nanofibers 53
Fig. 12. (A) Swelling properties from 0 h to 48 h, (B) swelling properties from 0 h to 2 h 54
Fig. 13. In vitro drug releasing behavior 55
Fig. 14. Cytotoxicity and cell proliferation of (A) HDF day 1 extracts, (B) HDF day 3 extracts, (C) HaCaT cells day 1 extracts, (D) HaCaT cells day 3 extracts, in day 1 and day 3 post-seeding determined using MTT assay 57
Fig. 15. Representative micrographs of live/dead HDF cell stained using FDA and PI at day 1 and 3 post-seeding 58
Fig. 16. Representative micrographs of live/dead HaCaT cell stained using FDA and PI at day 1 and 3 post-seeding 59
Fig. 17. (A) Antibacterial activity of nanofibrous scaffolds (1) PG, (2) PG I, (3) PG III, (4) PG V towards bacterial pathogens, (B) Representative graph showing the zone of... 61
Fig. 18. (A) Representative agar plates displaying appearance and disappearance of the microbial cells incubated with different types of nanofibrous scaffolds and (B)... 64
Fig. 19. Full-thickness excisional wound closure of ICR mice. (A) Representative images of the wound taken on days 0, 3, 7, 10, and 14. (B) Average post-surgery wound... 65
Fig. 20. Representative micrographs of (A) H & E, (B) Masson's trichrome stained tissue taken from the center of the wound, including both the scar and fully developed... 67