Clinical and Quality of Life Outcomes of a Combined Synthetic Scaffold and Autogenous Tissue Graft Procedure for Articular Cartilage Repair in the Knee

Background: Injuries to the articular cartilage of the knee often fail to heal properly, due to the hypocellular and avascular nature of this tissue. Subsequent disability can limit participation in sports and decrease quality of life. Subchondral bone perforations are used for the treatment of small defects. Larger lesions filling out the central portion becomes difficult, and scaffolds can be used as adjuvants, providing a matrix onto which the defect can be filled in completely and also autogenous cartilage grafts can be combined, acting as an inducer and improving healing quality, all in a single procedure.Methods: Evaluate the clinical and quality of life outcomes of patients with articular cartilage lesions of the knee undergoing repair via a microfracture technique combined with a synthetic scaffold and autogenous cartilage graft, with transosseous sutures and fibrin glue fixation, at 12 months of follow-up. Secondarily, assess whether combined procedures, previous surgical intervention, traumatic aetiology, lesion location, and age affect outcomes. Observational study of adult patients (age 18–66 years) with symptoms consistent with chondral or osteochondral lesions, isolated or multiple, ICRS grade III/IV, 2–12 cm2 in size. Patients with corrected angular deviations or instabilities were included. Those with BMI > 40 kg/m2, prior total or subtotal (> 30%) meniscectomy, second-look procedures, and follow-up < 6 months were excluded. Pain (VAS), physical activity (IKDC), osteoarthritis (WOMAC), and general quality of life (SF-36) were assessed.Results: 64 procedures were included, comprising 60 patients. There was significant improvement (P < 0.05) in VAS (5.92 to 2.37), IKDC score (33.44 to 56.33), and modified WOMAC score (53.26 to 75.93) after surgery. The SF-36 showed significant improvements in the physical and mental domains (30.49 to 40.23 and 46.43 to 49.84 respectively; both P < 0.05).Conclusions: Combination of microfractures, autogenous crushed cartilage graft, synthetic scaffold, and transosseous sutures with fibrin glue provides secure fixation for treatment of articular cartilage lesions of the knee. At 12-month follow-up, function had improved by 20 points on the IKDC and WOMAC, and quality of life by 10 points on the SF-36. Age > 45 years had a negative impact on outcomes.

Three-Dimensional Culture of Rhipicephalus (Boophilus) microplus BmVIII-SCC Cells on Multiple Synthetic Scaffold Systems and in Rotating Bioreactors

Tick cell culture facilitates research on the biology of ticks and their role as vectors of pathogens that affect humans, domestic animals, and wildlife. Because two-dimensional cell culture doesn’t promote the development of multicellular tissue-like composites, we hypothesized that culturing tick cells in a three-dimensional (3-D) configuration would form spheroids or tissue-like organoids. In this study, the cell line BmVIII-SCC obtained from the cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini, 1888), was cultured in different synthetic scaffold systems. Growth of the tick cells on macrogelatinous beads in rotating continuous culture system bioreactors enabled cellular attachment, organization, and development into spheroid-like aggregates, with evidence of tight cellular junctions between adjacent cells and secretion of an extracellular matrix. At least three cell morphologies were identified within the aggregates: fibroblast-like cells, small endothelial-like cells, and larger cells exhibiting multiple cytoplasmic endosomes and granular vesicles. These observations suggest that BmVIII-SCC cells adapted to 3-D culture retain pluripotency. Additional studies involving genomic analyses are needed to determine if BmVIII-SCC cells in 3-D culture mimic tick organs. Applications of 3-D culture to cattle fever tick research are discussed.

An Overview of the Application of Poly(lactic-co-glycolic) Acid (PLGA)-Based Scaffold for Drug Delivery in Cartilage Tissue Engineering

Poly(lactic-co-glycolic) acid (PLGA) has attracted a considerable amount of interest for biomedical application due to its biocompatibility, tailored biodegradation rate (depending on the molecular weight and copolymer ratio), approval for clinical use in humans by the U.S. Food and Drug Administration (FDA), the potential to change surface properties to create better interaction with biological materials and being suitable for export to countries and cultures where planting products with animals is unusable. For commercial use and research, PLGA has been widely studied to control small molecule drugs, proteins, and other macromolecules. This study aims to review the studies that used PLGA scaffolding and its composites as a scaffold and drug delivery in cartilage tissue engineering. It is concluded from the results that the PLGA scaffold as a synthetic scaffold, when combined with natural scaffolds or hybrids, strengthens its biological properties and performs its function better.

Synthetic Scaffold Systems for Increasing the Efficiency of Metabolic Pathways in Microorganisms

Microbes have been the preferred hosts for producing high-value chemicals from cheap raw materials. However, metabolic flux imbalance, the presence of competing pathways, and toxic intermediates often lead to low production efficiency. The spatial organization of the substrates, intermediates, and enzymes is critical to ensuring efficient metabolic activity by microorganisms. One of the most common approaches for bringing the key components of biosynthetic pathways together is through molecular scaffolds, which involves the clustering of pathway enzymes on engineered molecules via different interacting mechanisms. In particular, synthetic scaffold systems have been applied to improve the efficiency of various heterologous and synthetic pathways in Escherichia coli and Saccharomyces cerevisiae, with varying degrees of success. Herein, we review the recent developments and applications of protein-based and nucleic acid-based scaffold systems and discuss current challenges and future directions in the use of such approaches.

Honeycomb Scaffolds Capable of Achieving Barrier Membrane-Free Guided Bone Regeneration

Barrier membrane-free guided bone regeneration (GBR) with a synthetic scaffold may resolve the current challenges in vertical bone augmentation. To realize such GBR, we fabricated carbonate apatite honeycomb (HC) scaffolds...

Synthetic Scaffold/Dental Pulp Stem Cell (DPSC) Tissue Engineering Constructs for Bone Defect Treatment: An Animal Studies Literature Review

Background: Recently a greater interest in tissue engineering for the treatment of large bone defect has been reported. The aim of the present systematic review and meta-analysis was to investigate the effectiveness of dental pulp stem cells and synthetic block complexes for bone defect treatment in preclinical in vivo articles. Methods: The electronic database and manual search was conducted on Pubmed, Scopus, and EMBASE. The papers identified were submitted for risk-of-bias assessment and classified according to new bone formation, bone graft characteristics, dental pulp stem cells (DPSCs) culture passages and amount of experimental data. The meta-analysis assessment was conducted to assess new bone formation in test sites with DPSCs/synthetic blocks vs. synthetic block alone. Results: The database search identified a total of 348 papers. After the initial screening, 30 studies were included, according to the different animal models: 19 papers on rats, 3 articles on rabbits, 2 manuscripts on sheep and 4 papers on swine. The meta-analysis evaluation showed a significantly increase in new bone formation in favor of DPSCs/synthetic scaffold complexes, if compared to the control at 4 weeks (Mean Diff: 17.09%, 95% CI: 15.16–18.91%, p < 0.01) and at 8 weeks (Mean Diff: 14.86%, 95% CI: 1.82–27.91%, p < 0.01) in rats calvaria bone defects. Conclusion: The synthetic scaffolds in association of DPSCs used for the treatment of bone defects showed encouraging results of early new bone formation in preclinical animal studies and could represent a useful resource for regenerative bone augmentation procedures

Examining the Characteristics and Applications of Mesenchymal, Induced Pluripotent, and Embryonic Stem Cells for Tissue Engineering Approaches across the Germ Layers

The field of regenerative medicine utilizes a wide array of technologies and techniques for repairing and restoring function to damaged tissues. Among these, stem cells offer one of the most potent and promising biological tools to facilitate such goals. Implementation of mesenchymal stem cells (MSCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs) offer varying advantages based on availability and efficacy in the target tissue. The focus of this review is to discuss characteristics of these three subset stem cell populations and examine their utility in tissue engineering. In particular, the development of therapeutics that utilize cell-based approaches, divided by germinal layer to further assess research targeting specific tissues of the mesoderm, ectoderm, and endoderm. The combinatorial application of MSCs, iPSCs, and ESCs with natural and synthetic scaffold technologies can enhance the reparative capacity and survival of implanted cells. Continued efforts to generate more standardized approaches for these cells may provide improved study-to-study variations on implementation, thereby increasing the clinical translatability of cell-based therapeutics. Coupling clinically translatable research with commercially oriented methods offers the potential to drastically advance medical treatments for multiple diseases and injuries, improving the quality of life for many individuals.