Table 4.

Poly-L-(lactic acid) (PLLA) chemical composition as resulted from XPS measurements for each surface variant.

	PLLA_Control	PLLA_50	PLLA_50_N200	PLLA_50_N400	PLLA_50_O200	PLLA_50_O400
Elements (%)
C	67.1	74.8	76.2	71.7	75.6	75.3
O	32.9	25.2	23.8	28.3	24.4	24.7
N	-	-	-	-	-	-
C bonds (%)
–C–C–	53.5	69.4	68.0	60.9	72.0	73.7
–C–O–	23.4	19.3	21.0	21.1	17.1	17.4
–O=C–	23.1	11.3	11.0	17.0	10.9	8.9
O bonds (%)
–O=C–	55.6	63.0	62.9	60.1	62.7	61.6
–O–C–	44.4	37.0	37.1	39.9	37.3	38.4