New alginate-pullulan-bioactive glass composites with copper oxide for bone tissue regeneration trials

Abstract

Composites based on sodium alginate, pullulan, and bioactive SiO -CaO-P O glass-ceramics with copper oxide were prepared as capsules. The obtained samples were structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM), and their bioactivity and biocompatibility properties were also tested both in vitro and in vivo by XRD, FT-IR, SEM, and high-resolution transmission electron microscopy. The fibroblast and osteoblast cell viability assays have shown good proliferation rates for all investigated samples, whereas all composites exhibited a good in vivo tolerance. The recovered composites after 5 weeks' in vivo and in vitro trials evidenced clear macroscopic alterations; particularly, after soaking in simulated body fluid, they have a corn flake aspect, and after their in vivo inoculation, a globular shape is retained. Different crystalline shapes of hydroxyapatite were formed after in vitro and in vivo trials for the glass-ceramic-polymer composites, the in vitro precipitated apatite was found to be nodular, and the in vivo experiment led to needlelike crystallites formation. Histopathological results showed a good biocompatibility with no significant signs of rejection by the host tissue. These assessments performed on the composites indicate that the studied materials can be considered without any doubt suitable candidates for future bone regeneration applications.

Bone regeneration response in an experimental long bone defect orthotopically implanted with alginate‐pullulan‐glass‐ceramic composite scaffolds

“…Based on the previous in vivo assessment performed on the currently investigated samples (Popescu et al, ) one can consider without any doubt that these composites are suitable candidate for tissue regeneration, and therefore they were orthotopically implanted in experimental rats. To follow the evaluation of implanted materials, MRI experiments were performed to establish the nondestructive and noninvasive observation of the intermediate evolution of the areas of interest.…”

“…Prior the surgery, the implanted materials were characterized and described in detail in our previous study (Popescu et al, ). In that work, the FT‐IR spectra revealed the bond between polymers and glass‐ceramics and the XRD pattern shows that the composites have an amorphous character.…”

“…To acquire the polymeric mixture of 4% (wt/vol), alginate and pullulan powders were dissolved in 80 C ultrapure water at continuous stirring, the final solution having a weight ratio of 1:0.75 (Popescu et al, 2018;Sarker et al, 2014;Wong et al, 2011). The concentration of bioactive material into polymeric mixture was selected at 12.5% (Blaker, Day, Maquet, & Boccaccini, 2004;Day et al, 2004).…”

“…In the previous study, we were the first to demonstrate that composites containing two natural hydrophilic polysaccharides alginate and pullulan and a silicate bioactive glass‐ceramics exhibit in vitro and in vivo biocompatibility (Popescu et al, ). It was found that bioactive glass‐ceramics with 0.5 and 1.5 mol % CuO content have good antibacterial effect against Staphylococcus aureus (Popescu et al, ), and the composite scaffolds made of alginate‐pullulan and copper oxide containing bioactive glass‐ceramics (Alg‐Pll‐CuBG) can successfully support the proliferation of human fibroblast and osteoblast cells (Popescu et al, ). Thus, the aim of the present study is to assess the osteoconductive properties of macroporous Alg‐Pll‐xCuBG ( x = 0, 0.5, and 1.5 mol % in glass matrix) composite scaffolds in vivo and to examine their potential of reducing the healing time in a rat bone defect.…”

“…Based on the previous in vivo assessment performed on the currently investigated samples(Popescu et al, 2018) one can consider without F I G U R E 2 SEM micrograph of the Alg-Pll-0.5CuBG and Alg-Pll composites before and after lyophilization process. SEM, scanning electron microscopy any doubt that these composites are suitable candidate for tissue regeneration, and therefore they were orthotopically implanted inexperimental rats.…”