In-vitro cellular and in-vivo investigation of ascorbic acid and ß-glycerophosphate loaded gelatin/sodium alginate injectable hydrogels for urinary incontinence treatment.

Urinary incontinence is one of the most common disorders especially in adult women. In this study, cellular and in-vivo analyses were performed on (3-glycidyloxypropyl) trimethoxysilane (GPTMS) and CaCl2 cross-linked alginate and gelatin hydrogels containing ß-glycerophosphate and ascorbic acid to evaluate the regenerative potential as injectable compression agents for the treatment of urinary incontinence. The hydrogels were prepared with different percentages of components and were named as GA1 (7.2% w/v gelatin, 6% w/v sodium alginate, 0.5:1w/w GPTMS, CaCl2 1% (wt) sodium alginate, 50 µg/mL ascorbic acid, 1.5 mg/mL ß-glycerophosphate), GA2 (10% w/v gelatin, 8.5% w/v sodium alginate, 0.5:1 w/w GPTMS, CaCl2 1% (wt) sodium alginate, 50 µg/mL ascorbic acid, 1.5 mg/mL ß-glycerophosphate), and GA3 (10% (w/v) gelatin, 8.5% w/v sodium alginate, 1:1 w/w GPTMS, CaCl2 1% (wt) sodium alginate, 50 µg/mL ascorbic acid, 1.5 mg/mL ß-glycerophosphate) hydrogels. The results of cell studies showed that although all three samples supported cell adhesion and survival, the cellular behavior of the GA2 sample was better than the other samples. Animal tests were performed on the optimal GA2 sample, which showed that this hydrogel repaired the misfunction tissue in a rat model within 4 weeks and the molecular layer thickness was reached the normal tissue after this duration. It seems that these hydrogels, especially GA2 sample containing 10% (w/v) gelatin, 8.5% (w/v) sodium alginate, 0.5:1 (w/w) GPTMS, CaCl2 1% (wt) sodium alginate, 50 µg/mL ascorbic acid, and 1.5 mg/mL ß-glycerophosphate, can act as an injetable hydrogel for urinary incontinence treatment without the need for repeating the injection.

Mussel-inspired polydopamine induced the osteoinductivity to ice-templating PLGA-gelatin matrix for bone tissue engineering application.

In this study, poly(lactic-co-glycolic acid) (PLGA)-gelatin scaffolds were fabricated using the freeze-casting technique. Polydopamine (PDA) coating was applied on the surface of scaffolds to enhance the hydrophilicity, bioactivity, and cellular behavior of the composite constructs. Further, the synergistic effect of PDA coating and lamellar microstructure of scaffolds was evaluated on the promotion of properties. Based on morphological observations, freeze-casting constructs showed lamellar pore channels while the uniformity and pore size were slightly affected by deposition of PDA. The hydrophilicity and swelling capacity of the scaffolds were assessed using contact angle measurement and phosphate buffered saline absorption ratio. The results indicated a significant increment in water-matrix interactions following surface modification. The evaluation of the biodegradation ratio revealed the higher degree of degradation in PDA-coated samples owing to the presence of hydrophilic functional groups in the chemical structure of PDA. On the other hand, the bioactivity potential of PDA in the simulated body fluid solution confirmed the possibility of using coated constructs as a bone reconstructive substitute. The improvement of cellular attachment and filopodia formation in PDA-contained matrixes was the other benefit of the coating process. Furthermore, cellular proliferation and ALP activity were enhanced after PDA coating. The suggested PDA-coated PLGA-gelatin scaffolds can be applied in bone tissue regeneration.