Composite Membranes of Poly(ε-caprolactone) with Bisphosphonate-Loaded Bioactive Glasses for Potential Bone Tissue Engineering Applications

Abstract

Poly(ε-caprolactone) (PCL) is a bioresorbable synthetic polyester with numerous biomedical applications. PCL membranes show great potential in guided tissue regeneration because they are biocompatible, occlusive and space maintaining, but lack osteoconductivity. Therefore, two different types of mesoporous bioactive glasses (SiO2-CaO-P2O5 and SiO2-SrO-P2O5) were synthesized and incorporated in PCL thin membranes by spin coating. To enhance the osteogenic effect of resulting membranes, the bioglasses were loaded with the bisphosphonate drug ibandronate prior to their incorporation in the polymeric matrix. The effect of the composition of the bioglasses as well as the presence of absorbed ibandronate on the physicochemical, cell attachment and differentiation properties of the PCL membranes was evaluated. Both fillers led to a decrease of the crystallinity of PCL, along with an increase in its hydrophilicity and a noticeable increase in its bioactivity. Bioactivity was further increased in the presence of a Sr substituted bioglass loaded with ibandronate. The membranes exhibited excellent biocompatibility upon estimation of their cytotoxicity on Wharton’s Jelly Mesenchymal Stromal Cells (WJ-SCs), while they presented higher osteogenic potential in comparison with neat PCL after WJ-SCs induced differentiation towards bone cells, which was enhanced by a possible synergistic effect of Sr and ibandronate.

Mesoporous Bioactive Glasses Cytocompatibility Assessment: A Review of In Vitro Studies

“…The porosity of mesoporous bioactive glasses was exploited in 51% of the articles by incorporating adjuvants inside the pores, such as growth factors [ 62 ]. It is also common to add them to polymers to create composites, for example, polycaprolactone [ 90 , 95 ]. In 28% of the cases, the MBGs were doped, either with a metal-like element or with amino groups.…”

“…In certain clinical situations, MBGs or MBG-based materials do not make direct contact with cells, however, their dissolution products or leachates could reach targeted cells; this could explain the significant use of extraction techniques (indirect cultivation setting) when assessing cytocompatibility of materials [ 21 , 55 , 59 , 81 , 91 , 95 , 100 , 101 ]. In a test based on direct contact, the material sample is in physical contact with the cells; this system also has some clinical relevance.…”

Research Progress of Bioactive Glass and Its Application in Orthopedics

“…[132] In 2019, Terzopoulou et al incorporated ibandronate (IBA) in BGs and prepared thin PCL composite membranes using the spin coating technology (Figure 14). [133] The BGs reduced the crystallinity of PCL and improved the hydrophilicity and bioactivity of the PCL. Overall, Sr and IBA improves the oste-ogenic potential of neat PCL.…”

“…Implants improve the quality of patients' life by replacing or repairing damaged or degenerated tissues/organs. However, in orthopedic applications, whether [133] Copyright 2019, The Authors, published by MDPI. C) Reproduced with permission.…”

“…C) The surface morphology of the PDLLA-based composite membranes assessed using microscope-based white light interferometry: a) pure PDLLA membrane, PDLLA membrane supplemented with b) 5 wt% micro-scale BG (m-BG), c) 10 wt% m-BG, d) 20 wt% m-BG. A,B) Reproduced under the terms of the CC-BY 4.0 license [133]. Copyright 2019, The Authors, published by MDPI.…”