Promotion of skin fibroblasts collagen synthesis by polydioxanone mats combined with concentrated growth factor extracts

Polydioxanone Enhances Bone Regeneration After Resection and Reconstruction of Rat Femur with rhBMP2

The aim of this study was to assess the bone regeneration potential of a polydioxanone (PDO) scaffold together with recombinant human bone morphogenetic protein-2 (rhBMP-2) for the reconstruction of large bone defect. In total, 24 male rats (6 months old) were subjected to bilateral femoral stabilization using titanium plates to create a 2 mm gap, and reconstruction using rhBMP-2 (Infuse®; 3.25 μg). The bone defects were covered with PDO (PDO group), or with titanium mesh (Ti group). Animals were euthanized on days 14 and 60. Simultaneously, 16 rats received PDO and Ti in their dorsum for the purpose of biocompatibility analysis at 3, 5, 7, and 10 days postoperatively. X-ray densitometry showed a higher density in the PDO group on day 14. On day 60, coverage of the bone defect with PDO showed a larger quantity of newly formed bone than that found for the Ti group, a lower inflammatory infiltrate value, and a more significant number of blood vessels on day 14. By immunohistochemical assessment, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) showed higher labeling on day 14 in the PDO group. On day 60, bone morphogenetic protein-2 (BMP-2) showed higher labeling in the PDO group, whereas Ti showed higher labeling for osteoprotegerin, nuclear factor kappa B ligand-activating receptor, RUNX2, and OCN. Furthermore, biocompatibility analysis showed a higher inflammatory response in the Ti group. The PDO scaffold enhanced bone regeneration when associated with rhBMP-2 in rat femur reconstruction. Impact statement Regeneration of segmental bone defects is a difficult task, and several techniques and materials have been used. Recent advances in the production of synthetic polymers, such as polydioxanone (PDO), produced by three-dimensional printing, have shown distinct characteristics that could improve tissue regeneration even in an important bone defect. The present preclinical study showed that PDO membranes used as scaffolds to carry recombinant human bone morphogenetic protein-2 (rhBMP-2) improved bone tissue regeneration by more than 8-fold when compared with titanium mesh, suggesting that PDO membranes could be a feasible and useful material for use in guided bone regeneration. (In English, viable is only used for living creatures capable of sustaining life.

Novel Applications of Concentrated Growth Factors in Facial Rejuvenation and Plastic Surgery

Concentrated growth factor (CGF), which is a third-generation platelet concentrate product, exhibits good potential for repair and regeneration of soft and hard tissues, and has gradually attracted attention in the field of cosmetic plastic surgery. The purpose of this review is to summarize the application and research of CGF in the field of facial rejuvenation and plastic surgery. A comprehensive review of the literature about the applications of CGF in facial rejuvenation and plastic surgery was conducted in PubMed, Ovid MEDLINE, and Web of Science. According to the inclusion and exclusion criteria, a total of 22 articles were included in this review. In recent years, CGF has been applied in many aspects in the field of facial rejuvenation and plastic surgery, including skin photoaging, repairment of soft-tissue defects, rhinoplasty, hair loss, autologous fat transplantation, and scars. In addition, no significant adverse reactions have been reported so far. CGF is rich in high-concentration growth factors, which has great potential and application prospects in facial rejuvenation and plastic surgery. However, the applications of CGF still have some problems, such as the mechanism, time of decomposition, and long-term efficacy and safety, which are needed to be resolved in future.

Optimization of a concentrated growth factor/mesoporous bioactive glass composite scaffold and its application in rabbit mandible defect regeneration

Maxillofacial bone defect repair and regeneration remains a tremendous challenge in the field of stomatology. However, the limited osteoinductivity of artificial materials and the high cost of bioactive agents restrain their clinical translation. This study aimed to construct an economical and efficient concentrated growth factor/mesoporous bioactive glass (CGF/MBG) composite scaffold for bone regeneration. The biochemical composition and biological effects of different forms of CGFs were systematically compared, and the results showed that CGF-conditioned medium effectively promoted proliferation, migration and osteogenesis of allogenic BMSCs. Gel phase CGF (gpCGF) exhibited superior bioactivity and osteoinductivity to liquid phase CGF (lpCGF) and liquid/gel mixed phase CGF (lgpCGF), and was further applied to construct CGF/MBG scaffolds. In vitro studies demonstrated that co-culture with gpCGF-conditioned medium further enhanced the biocompatibility of MBG, increasing cell adhesion and proliferation on the scaffold. On this basis, two compositing approaches to construct the scaffold by fibrin gel formation (CGF/FG/MBG) and freeze-drying (fdCGF/MBG) were applied, and the biological efficacy of CGFs was compared in vivo. In a rabbit mandibular defect model, higher osteogenic efficiency in in situ bone regeneration of CGF/FG/MBG composite scaffolds was proved, compared with fdCGF/MBG. Taken together, the CGF/FG/MBG composite scaffold is expected to be an efficient bone repairing therapy for clinical translation, and the CGF-composited scaffold using gpCGF and the fibrin gel formation method is a promising way to enhance the bioactivity and osteoinductivity of current clinical bone repairing materials, providing new thoughts on the development of future orthopedic biomaterials.

Design and development of polydioxanone scaffolds for skin tissue engineering manufactured via green process

Fiber spinning technologies attracted a great interest since the beginning of the last century. Among these, electrospinning is a widely diffuse technique; however, it presents some drawbacks such as low fiber yield, high energy demand and the use of organic solvents. On the contrary, centrifugal spinning is a more sustainable method and allows to obtain fiber using centrifugal force and melted materials. The aim of the present work was the design and the development of polydioxanone (PDO) microfibers intended for tissue engineering, using centrifugal spinning. PDO, a bioresorbable polymer currently used for sutures, was selected as low melting polyester and DES (deep eutectic solvents), either choline chloride/citric acid (ChCl/CA) or betaine/citric acid (Bet/CA) 1:1 M ratio, were used to improve PDO spinnability. Physical mixtures of DES and PDO were prepared using different weight ratios. These were then poured into the spinneret and melted at 140 °C for 5 min. After the complete melting, the blends were spun for 1 min at 700 rpm. The fibers were characterized for physico chemical properties (morphology; dimensions; chemical structure; thermal behavior; mechanical properties). Moreover, the preclinical investigation was performed in vitro (biocompatibility, adhesion and proliferation of fibroblasts) and in vivo (murine burn/excisional model to assess safety and efficacy). The multidisciplinary approach allowed to obtain an extensive characterization to develop PDO based microfibers as medical device for implant to treat full thickness skin wounds.

Manganese silicate nanospheres-incorporated hydrogels：starvation therapy and tissue regeneration

To prevent postoperative skin tumor recurrence and repair skin wound, a glucose oxidase (GOx)-loaded manganese silicate hollow nanospheres (MS HNSs)-incorporated alginate hydrogel (G/MS-SA) was constructed for starvation-photothermal therapy and skin tissue regeneration. The MS HNSs showed a photothermal conversion efficiency of 38.5%, and endowed composite hydrogels with satisfactory photothermal effect. Taking advantage of the catalytic activity of Mn ions, the composite hydrogels could decompose hydrogen peroxide (H2O2) into oxygen (O2), which can alleviate the problem of tumor hypoxia microenvironment and endow GOx with an ability to consume glucose in the presence of O2 for tumor starvation. Meanwhile, hyperthermia triggered by near infrared (NIR) irradiation could not only accelerate the reaction rate of H2O2 decomposition by MS HNSs and glucose consumption by GOx, but also ablate tumor cells. The anti-tumor results showed that synergistic effect of starvation-photothermal therapy led to the highest death rate of tumor cells among all groups, and its anti-tumor effect was obviously improved as compared with that of single photothermal treatment or starvation treatment. Interestingly, the introduction of MS HNSs into hydrogels could distinctly promote the epithelialization of the wound beds by releasing Mn ions as compared with the hydrogels without MS HNSs. It is expected that such a multifunctional platform with starvation-photothermal therapy will be promising for treating tumor-caused skin defects in combination of its regeneration bioactivity in the future.

Considerations for Clinical Use of Concentrated Growth Factor in Maxillofacial Regenerative Medicine

Different strategies have been utilized to facilitate mineralized/soft tissues. Concentrated growth factor (CGF) emerges as a promising biomaterial for regenerative therapy due to high levels of platelets, growth factors, and nucleated cells entrapped in the fibrin scaffold. This review aimed to collect extensive studies on CGF used in maxillofacial regenerative medicine, discussing current obstacles, and expressing some considerations of CGF use. Articles were retrieved systematically without time limitation. In total, 27 human studies were included and separated accordingly. In general, CGF has been most evaluated in implant related therapy and maxillofacial bone regeneration where a majority of articles have revealed favorable outcomes. Little studies have supported the effects on improving probing periodontal depth reductions and clinical attachment level gains for intrabony and furcation defect regeneration. Very little data with high-level evidence was available directly to investigate its effects on the soft tissue regeneration and postoperative complications reduction. The evidence supporting the clinical efficacy of CGF in maxillofacial regenerative medicine is limited. Some conflicting results are worrisome. In addition, the characterization of CGF preparation protocols and CGF's components was not performed in most studies. Further studies should make a consensus on standardized end-product of CGF including characterization of protocols and optimal ratio of CGF' components. Defined algorithms and evidence-based protocols for the clinical use of CGF should be also available.