In Vivo Bone Regeneration Capacity of Multiscale Porous Polycaprolactone-Based High Internal Phase Emulsion (PolyHIPE) Scaffolds in a Rat Calvarial Defect Model

Abstract

Globally, one of the most common tissue transplantation procedures is bone grafting. Lately, we have reported the development of polymerized high internal phase emulsions (PolyHIPEs) made of photocurable polycaprolactone (4PCLMA) and shown their potential to be used as bone tissue engineering scaffolds in vitro. However, it is essential to evaluate the in vivo performance of these scaffolds to investigate their potential in a clinically more relevant manner. Therefore, in this study, we aimed to compare in vivo performances of macroporous (fabricated using stereolithography), microporous (fabricated using emulsion templating), and multiscale porous (fabricated using emulsion templating and perforation) scaffolds made of 4PCLMA. Also, 3Dprinted macroporous scaffolds (fabricated using fused deposition modeling) made of thermoplastic polycaprolactone were used as a control. Scaffolds were implanted into a critical-sized calvarial defect, animals were sacrificed 4 or 8 weeks after implantation, and the new bone formation was assessed by micro-computed tomography, dental radiography, and histology. Multiscale porous scaffolds that include both micro-and macropores resulted in higher bone regeneration in the defect area compared to only macroporous or only microporous scaffolds. When one-grade porous scaffolds were compared, microporous scaffolds showed better performance than macroporous scaffolds in terms of mineralized bone volume and tissue regeneration. Micro-CT results revealed that while bone volume/tissue volume (Bv/Tv) values were 8 and 17% at weeks 4 and 8 for macroporous scaffolds, they were significantly higher for microporous scaffolds, with values of 26 and 33%, respectively. Taken together, the results reported in this study showed the potential application of multiscale PolyHIPE scaffolds, in particular, as a promising material for bone regeneration.

Development of tissue-engineered vascular grafts from decellularized parsley stems

“…The morphology of the decellularized parsley stems was investigated via scanning electron microscopy (SEM). 58–60 Before imaging, the samples were dehydrated using a previously described biological sample preparation protocol using a chemical drying agent, HMDS. 52 Dry samples were then coated with gold at a current of 10 mA for 90 seconds using a gold sputter (Edwards sputter coater S150B, Crawley, England) and imaged via SEM (FEI QUANTA 250 FEG, Hillsboro, Oregon, USA).…”

Unique Crystallization Characteristics of Pickering High Internal Phase Emulsion Templated Porous Constructs

“…Additionally, γ radiation cross-linked PCL has also been utilized to study the crystallization behavior of cross-linked PCL . Recently, HIPE-templated PCL polyHIPEs have attracted significant interest due to the favorable biological properties of PCL along with the structural tunability of polyHIPEs. − Initially developed using surfactant-stabilized HIPEs, the methodology was further expanded with the introduction of nanoparticle (NP) stabilized Pickering-HIPEs which facilitated the single-step fabrication of nanocomposite cross-linked PCL polyHIPEs . Considering the potential growth of HIPE-templated PCL polyHIPEs and Pickering polyHIPEs, it was desirable to study its crystallization behavior which would not only provide better insights into the molecular dynamics of HIPE templated structures but also expand its applicability to other systems.…”

Quantitative Evaluation of the Pore and Window Sizes of Tissue Engineering Scaffolds on Scanning Electron Microscope Images Using Deep Learning

“…Open pores are connected to both the surface and neighboring pores, whereas closed pores are not connected to either. From a biological point of view, open porosity is advantageous because it is essential for cell migration, nutrient transmission through the scaffold, waste removal, and the integration of the material with the host tissue. , Polymerized HIPEs (also known as PolyHIPEs) are used to create open porous scaffolds (Figure ) with an average pore diameter of 1–100 μm that permits cell infiltration. , …”