Poly‐ϵ‐caprolactone/hydroxyapatite composites for bone regeneration: In vitro characterization and human osteoblast response

Abstract

Polycaprolactone (PCL), a semicrystalline linear resorbable aliphatic polyester, is a good candidate as a scaffold for bone tissue engineering, due to its biocompatibility and biodegradability. However, the poor mechanical properties of PCL impair its use as scaffold for hard tissue regeneration, unless mechanical reinforcement is provided. To enhance mechanical properties and promote osteoconductivity, hydroxyapatite (HA) particles were added to the PCL matrix: three PCL-based composites with different volume ratio of HA (13%, 20%, and 32%) were studied. Mechanical properties and structure were analysed, along with biocompatibility and osteoconductivity. The addition of HA particles (in particular in the range of 20% and 32%) led to a significant improvement in mechanical performance (e.g., elastic modulus) of scaffold. Saos-2 cells and osteoblasts from human trabecular bone (hOB) retrieved during total hip replacement surgery were seeded onto 3D PCL samples for 1-4 weeks. Following the assessment of cell viability, proliferation, morphology, and ALP release, HA-loaded PCL was found to improve osteoconduction compared to the PCL alone. The results indicated that PCL represents a potential candidate as an efficient substrate for bone substitution through an accurate balance between structural/ mechanical properties of polymer and biological activities.

Calcium orthophosphate-based biocomposites and hybrid biomaterials

“…The composites were found to be biodegradable and might be applied as cancellous or trabecular bone replacement material or for cartilage regeneration. Both the mechanical performance and biocompatibility in osteoblast cell culture of PCL were shown to be strongly increased when HA was added [358]. Several preparation techniques of PCL/HA composites are known.…”

Augmentation of bone defect healing using a new biocomposite scaffold: An in vivo study in sheep

“…However, despite allowing deformation of the scaffold, which is necessary for application in total knee revision, these polymer scaffolds do not offer good enough mechanical properties to resist significant loadings. To overcome this mechanical drawback ceramic-polymer composites have gained increasing interest [6][7][8]. In particular, a biocomposite of controlled porosity combining b-tricalcium phosphate (b-TCP) and poly(L-lactic acid) (PLA) was obtained by supercritical gas foaming [9].…”

Physical properties and cellular responses to crosslinkable poly(propylene fumarate)/hydroxyapatite nanocomposites

“…However, it is very brittle and cannot be applied to the load-bearing site directly [3][4][5]. To overcome these limitations, HA has been incorporated with natural biomacromolecules such as collagen [6][7][8] and gelatin [9,10], or synthetic polymers such as poly (α-hydroxyl acids) [11][12][13][14][15], poly (ε-caprolactone) (PCL) [16,17], polyamide [18], and polymethylmethacrylate (PMMA) [19] to prepare composites using a variety of methods including surface coating, grafting, direct mixing, and biomimetic precipitation [10,11,[20][21][22][23]. Particularly, polymer/HA nanocomposites have improved mechanical properties and enhanced cell attachment, spreading, and proliferation on their surfaces by adding nano-sized HA to modify the polymer's characteristics and/or strengthen the polymer matrix [24,25].…”