Rsing samples in PBS in 37uC incubator to mimic the physiological conditions. At predetermined time-points, the PBS was entirely replenished to maintain sink condition. And PBS containing the released peptide was tested using the micro-bicinchoninic acid protein assay (Pierce). The samples were prepared in accordance to the manufacturer’s protocol and the absorbance detection was tested at 526 nm wavelength using the UV-Vis spectrophotometer (UV2501, Shimadzu).4. In vitro Degradation and Mass LossThe degradation study was carried out by immersing the films in PBS and replenished at pre-determined time-points. At the predetermined time-points, samples were rinsed with deionized water and dried in 37uC vacuum oven for 1 week before characterization. The degree of degradation was monitored via the changes in molecular mass which was measured using the gel permeability chromatography (GPC, Agilent series 1100). And mass loss was determined by comparing the initial and final masses of films at each time-point and the calculation for percentage mass loss is shown in the following equation. Mass loss Mi { Mf |100 MiMaterials and Methods 1. MaterialsCD-NP and Human Cardiotrophin-1 (CT-1) were obtained from the American Peptide Company and GenWay (USA) respectively. Poly (e-caprolactone) (PCL) (Mn: 80,000 g/mol) was purchased from Sigma-Aldrich (USA). Phosphate buffer solution (PBS), pH 7.4 was purchased from OHME scientific. All organic solvents were of analytical grade and were used as received.2. Sample PreparationThe polymer solution was prepared by Title Loaded From File dissolving 0.9 g PCL pellets in 5 mL of dichloromethane (DCM) and stirred continuously to obtain homogenous solution. The peptide solution was prepared separately, by dissolving 1 wt of CD-NP in water (150 mL) or ethanol (1000 mL) according to their co-solvent system formulation. Subsequently, the polymer solution and peptide solution were added together and emulsified, where the emulsification duration was monitored. Finally, the solution was solvent cast on glass panels via an automatic film applicator. The films were left in room temperature ambience overnight before relocating to the 37uC vacuum oven for 7 days to remove any residual solvent. The residual solvent was verified to be less than 1 wt using the Title Loaded From File thermogravimetric analyzer (TGA, TA Instruments Q500). To obtain different release rates, 3 biodegradable polymeric films encapsulating CD-NP were developed using different cosolvent systems at varied emulsification conditions. Film 1 was prepared using the water/DCM co-solvent system, emulsified for 10 minutes. Film 2 was prepared using the ethanol/DCM, where the effect of emulsification duration was negligible. Film 3 was prepared using the water/DCM co-solvent system, emulsified for 1 hour. Table 1 gives a summary of the manufacturing condition and initial release classification of the formulations. Table 1. Summary of formulation information.5. Surface MorphologicalSamples were coated with gold for 20 seconds using the gold sputter machine under argon atmosphere. Initial and post immersion surface morphology were viewed using the scanning electron microscopy 23977191 (SEM) (AS Jeol 6360) at 3 kV.6. In vitro Human Cardiac Fibroblast (HCF) CultureHuman cardiac fibroblast (HCF) cells were purchased from lonza. Cells were grown and maintained using fibroblast growth medium (FGM, Lonza) consisting of recombinant human insulin, r-Human fibroblast growth factor-B (rhFGF-B), gentamicin sulfate ampho.Rsing samples in PBS in 37uC incubator to mimic the physiological conditions. At predetermined time-points, the PBS was entirely replenished to maintain sink condition. And PBS containing the released peptide was tested using the micro-bicinchoninic acid protein assay (Pierce). The samples were prepared in accordance to the manufacturer’s protocol and the absorbance detection was tested at 526 nm wavelength using the UV-Vis spectrophotometer (UV2501, Shimadzu).4. In vitro Degradation and Mass LossThe degradation study was carried out by immersing the films in PBS and replenished at pre-determined time-points. At the predetermined time-points, samples were rinsed with deionized water and dried in 37uC vacuum oven for 1 week before characterization. The degree of degradation was monitored via the changes in molecular mass which was measured using the gel permeability chromatography (GPC, Agilent series 1100). And mass loss was determined by comparing the initial and final masses of films at each time-point and the calculation for percentage mass loss is shown in the following equation. Mass loss Mi { Mf |100 MiMaterials and Methods 1. MaterialsCD-NP and Human Cardiotrophin-1 (CT-1) were obtained from the American Peptide Company and GenWay (USA) respectively. Poly (e-caprolactone) (PCL) (Mn: 80,000 g/mol) was purchased from Sigma-Aldrich (USA). Phosphate buffer solution (PBS), pH 7.4 was purchased from OHME scientific. All organic solvents were of analytical grade and were used as received.2. Sample PreparationThe polymer solution was prepared by dissolving 0.9 g PCL pellets in 5 mL of dichloromethane (DCM) and stirred continuously to obtain homogenous solution. The peptide solution was prepared separately, by dissolving 1 wt of CD-NP in water (150 mL) or ethanol (1000 mL) according to their co-solvent system formulation. Subsequently, the polymer solution and peptide solution were added together and emulsified, where the emulsification duration was monitored. Finally, the solution was solvent cast on glass panels via an automatic film applicator. The films were left in room temperature ambience overnight before relocating to the 37uC vacuum oven for 7 days to remove any residual solvent. The residual solvent was verified to be less than 1 wt using the thermogravimetric analyzer (TGA, TA Instruments Q500). To obtain different release rates, 3 biodegradable polymeric films encapsulating CD-NP were developed using different cosolvent systems at varied emulsification conditions. Film 1 was prepared using the water/DCM co-solvent system, emulsified for 10 minutes. Film 2 was prepared using the ethanol/DCM, where the effect of emulsification duration was negligible. Film 3 was prepared using the water/DCM co-solvent system, emulsified for 1 hour. Table 1 gives a summary of the manufacturing condition and initial release classification of the formulations. Table 1. Summary of formulation information.5. Surface MorphologicalSamples were coated with gold for 20 seconds using the gold sputter machine under argon atmosphere. Initial and post immersion surface morphology were viewed using the scanning electron microscopy 23977191 (SEM) (AS Jeol 6360) at 3 kV.6. In vitro Human Cardiac Fibroblast (HCF) CultureHuman cardiac fibroblast (HCF) cells were purchased from lonza. Cells were grown and maintained using fibroblast growth medium (FGM, Lonza) consisting of recombinant human insulin, r-Human fibroblast growth factor-B (rhFGF-B), gentamicin sulfate ampho.