  The current management of critical size bone defects (CSBDs) remains
challenging and requires multiple surgeries. To reduce the number of surgeries,
wrapping a biodegradable fibrous membrane around the defect to contain the
graft and carry biological stimulants for repair is highly desirable.
Poly(epsilon-caprolactone) (PCL) can be utilised to realise nonwoven fibrous
barrier-like structures through free surface electrospinning (FSE). Human
periosteum and induced membrane (IM) samples informed the development of an FSE
membrane to support platelet lysate (PL) absorption, multipotential stromal
cells (MSC) growth, and the prevention of cell migration. Although thinner than
IM, periosteum presented a more mature vascular system with a significantly
larger blood vessel diameter. The electrospun membrane (PCL3%-E) exhibited
randomly configured nanoscale fibres that were successfully customised to
introduce pores of increased diameter, without compromising tensile properties.
Additional to the PL absorption and release capabilities needed for MSC
attraction and growth, PCL3%-E also provided a favourable surface for the
proliferation and alignment of periosteum- and bone marrow derived-MSCs, whilst
possessing a barrier function to cell migration. These results demonstrate the
development of a promising biodegradable barrier membrane enabling PL release
and MSC colonisation, two key functionalities needed for the in situ formation
of a transitional periosteum-like structure, enabling movement towards
single-surgery CSBD reconstruction.
