Electrospun polycaprolactone matrices with tensile properties suitable for soft tissue engineering

Figures & data

Table I. Tensile property of PCL with different solvents.

S.no	Polymer	Solvent	Tensile strength in Mega Pascals	Tissue studies/constructs	References
1	10% Polycaprolactone	TFE	2.7	Bone tissue engineering (bone marrow stromal cells)	Zhang et al. (2005)
2	14% Polycaprolactone	Tetrahydrofuran/dimethylformamide (1:1)	2.1 ± 0.4	Bone tissue engineering (Human mesenchymal stromal cells – fibrochondrocytes)	Li et al. (2007)
3	Polycaprolactone	Acetone	1.3 ± 0.04	ND	Johnson et al. (2009)
4	15% Polycaprolactone	Dichloromethane/methanol	3.5 ± 1.1	Neural tissue engineering	Hackett et al. (2010)
5	12.5% PCL/collagen (separately electrospun	HFP	5.0 ± 1.7	Neural tissue engineering (stem cells-neural cells)
6	PCL/collagen (1/1)	Acetic acid	1.2 ± 0.4	ND	Yogeshwar et al. (2011)
7	Polycaprolactone	Acetic acid	1.88 ± 1.3	ND
8	10% Polycaprolactone	TFE	1.74 ± 0.18	Ocular surface engineering (Limbal epithelial cells)	Sharma et al. (2011)
9	5% polycaprolactone	HFP/TFA (9/1)	15.4 ± 2.3	Skin tissue engineering (human dermal fibroblast)	Kim et al. (2012a)
10	5% PCL/chitin (1/1)	HFP/TFA (9/1)	34.1 ± 6.8	Skin tissue engineering (human dermal fibroblast)

Depicts the review of solvents used to electrospin polycaprolactone and their resultant higher modulus, in MPa.

Table II. Porosity measurement of binary images with 3 different thresholds.

Sample	Magnification	Top layer (P1)	Middle layer (P2)	Lower layer (P3)	Average pore size
1	2000	75.9	56.7	19.2	50.6
2	2000	80.2	56.9	33.7	56.9
3	2000	81.9	54.1	26.3	54.1
4	2000	73.2	56.1	18.0	49.7
				MEAN	52.8
				STDEV	2.36

Represents the porosity measurements of 4 SEM images with 2000X magnifications using ImageJ software. Porosity percentages of 3 threshold layers of the nanofiber mats were measured as P1, P2 and P3.Total porosity percentage was the average of the three, and the overall percentage of porosity was estimated by calculating the mean and standard deviation.

Table III. Tensile property of the nanofibrous matrices collected for 4 h.

Nanofibrous membrane	Tensile stress (kPa)	Elongation (%)	Modulus (elasticity) (kPa)
Sample 1	33.47	174.56	31.41
Sample 2	28.68	137.29	27.05
Sample 3	33.18	122.22	34.26
Sample 4	33.92	82.73	49.23
Sample 5	18.03	163.15	19.66
Sample 6	43.55	95.77	54.67
Mean	31.80	129.29	36.05
SD	8.32	36.33	13.38

The tabular column represents the mean and standard deviation of the tensile strength, elongation, and Young's modulus of 6 different samples of polycaprolactone nanofibrous matrices.

Figure 1. (A), (B), and (C). SEM of electrospun membranes of polycaprolactone, with the concentrations of 10%, 12%, and 15% (Magnification – 5000×).

Figure 2. Depicts the graphical representation of the measurement of fiber diameter of electrospun matrices with different concentrations of 10% wt, 12% wt, and 15% wt, using ImageJ software. The fiber diameter increases with an increase in concentration.

Figure 3. Biocompatibility of the polycaprolactone membrane, evaluated by the MTT assay using L6 rat skeletal myoblast cell growth tested at 3 different time points (2, 4, and 6, days in culture).

Figure 4. Cryosectioned polycaprolactone electrospun matrices seeded with rat skeletal myoblasts were stained for muscle-specific actin with FITC (A), DAPI for nuclear staining (B), and merged (C).

Figure 5. Cryosectioned matrices seeded with rat skeletal myoblasts were stained with (A) Phase contrast, (B) nuclear staining with DAPI, (C) desmin with FITC, and (D) Merged image of all.

Figure 6. Agarose electrophoresis image of RT-PCR analysis of desmin and GAPDH. (Lanes 1 and 2) – Desmin 3D and 2D. (Lanes 4 and 5) – GAPDH 3D and 2D.

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