Characterization of the distributions of collagen and PGs content in the decellularized book-shaped enthesis scaffolds by SR-FTIR.

BACKGROUND: Bone-tendon interface (enthesis) plays a pivotal role in relaxing load transfer between otherwise structurally and functionally distinct tissue types. Currently, decellularized extracellular matrix (DEM) from enthesis provide a natural three-dimensional scaffold with tissue-specific orientations of extracellular matrix molecules for enthesis regeneration, however, the distributions of collagen and PGs content in the decellularized book-shaped enthesis scaffolds from rabbit rotator cuff by SR-FTIR have not been reported. METHODS: Native enthesis tissues (NET) harvested from rabbit rotator cuff were sectioned into cuboid (about 30 mm × 1.2 mm × 10 mm) for decalcification. The decellularized book-shaped enthesis scaffolds and intrinsic ultrastructure were evaluated by histological staining and scanning electron microscopy (SEM), respectively. The distributions of collagen and PGs content in the decellularized book-shaped enthesis scaffolds from rabbit rotator cuff were also measured innovatively by SR-FTIR. RESULTS: The decellularized book-shaped enthesis scaffolds from rabbit rotator cuff were successfully obtained. Histomorphology and SEM evaluated the effect of decellularization and the structure of extracellular matrix during decellularization. After mechanical testing, the failure load in the NET group showed significantly higher than that in the DEM group (P < 0.05). Meanwhile, the stiffness of the DEM group was significantly lower than the NET group. Furthermore, the distributions of collagen and PGs content in the decellularized book-shaped enthesis scaffolds were decreased obviously after decellularization by SR-FTIR quantitative analysis. CONCLUSION: SR-FTIR was applied innovatively to characterize the histological morphology of native enthesis tissues from rabbit rotator cuff. Moreover, this technology can be applied for quantitative mapping of the distribution of collagen and PGs content in the decellularized book-shaped enthesis scaffolds.

Pan-cancer Comprehensive Analysis Identified EGFR as a Potential Biomarker for Multiple Tumor Types.

The epidermal growth factor receptor (EGFR) has been extensively studied for its critical role in the development and progression of various malignancies. In this comprehensive pan-cancer analysis, we investigated the potential of EGFR as a biomarker across multiple tumor types; a comprehensive analysis of EGFR gene mutation and copy number variation was conducted using cBioPortal and other tools. Utilizing multi-omics datasets from The Cancer Genome Atlas (TCGA), we analyzed EGFR's expression patterns, prognostic implications, genetic mutations, and molecular interactions in different cancers. Our findings revealed frequent dysregulation of EGFR in several tumor types, including lung cancers and glioblastoma multiforme. High EGFR expression was consistently associated with poor clinical outcomes, such as reduced overall survival, disease-free survival, and progression-free survival. Genetic alteration analysis indicated a high frequency of EGFR mutations and copy number variations, particularly in glioblastoma multiforme. Additionally, our study suggests a complex relationship between EGFR expression and cancer-associated fibroblast infiltration, which may contribute to an immunosuppressive tumor microenvironment. These findings underscore the clinical relevance of EGFR as a prognostic biomarker and therapeutic target, emphasizing the need for further research and the development of targeted therapies to enhance patient outcomes in cancers with EGFR alterations. The co-expression network of EGFR with genes and proteins involved in cell cycle regulation and mitotic control provided insights into the molecular mechanisms of oncogenesis.

Optimized Allogenic Decellularized Meniscal Scaffold Modified by Collagen Affinity Stromal Cell-Derived Factor SDF1α for Meniscal Regeneration: A 6- and 12-Week Animal Study in a Rabbit Model.

BACKGROUND: Total meniscectomy for treating massive meniscal tears may lead to joint instability, cartilage degeneration, and even progressive osteoarthritis. The meniscal substitution strategies for advancing reconstruction of the meniscus deserve further investigation. HYPOTHESIS: A decellularized meniscal scaffold (DMS) modified with collagen affinity stromal cell-derived factor (C-SDF1α) may facilitate meniscal regeneration and protect cartilage from abrasion. STUDY DESIGN: Controlled laboratory study. METHODS: The authors first modified DMS with C-SDF1α to fabricate a new meniscal graft (DMS-CBD [collagen-binding domain]). Second, they performed in vitro studies to evaluate the release dynamics, biocompatibility, and differentiation inducibility (osteogenic, chondrogenic, and tenogenic differentiation) on human bone marrow mesenchymal stem cells. Using in vivo studies, they subjected rabbits that received medial meniscectomy to a transplantation procedure to implement their meniscal graft. At postoperative weeks 6 and 12, the meniscal regeneration outcomes and chondroprotective efficacy of the new meniscal graft were evaluated by macroscopic observation, histology, micromechanics, and immunohistochemistry tests. RESULTS: In in vitro studies, the optimized DMS-CBD graft showed notable biocompatibility, releasing efficiency, and chondrogenic inducibility. In in vivo studies, the implanted DMS-CBD graft after total meniscectomy promoted the migration of cells and extracellular matrix deposition in transplantation and further facilitated meniscal regeneration and protected articular cartilage from degeneration. CONCLUSION: The new meniscal graft (DMS-CBD) accelerated extracellular matrix deposition and meniscal regeneration and protected articular cartilage from degeneration. CLINICAL RELEVANCE: The results demonstrate that the DMS-CBD graft can serve as a potential meniscal substitution after meniscectomy.

Improved charge extraction in inverted perovskite solar cells with dual-site-binding ligands.

Inverted (pin) perovskite solar cells (PSCs) afford improved operating stability in comparison to their nip counterparts but have lagged in power conversion efficiency (PCE). The energetic losses responsible for this PCE deficit in pin PSCs occur primarily at the interfaces between the perovskite and the charge-transport layers. Additive and surface treatments that use passivating ligands usually bind to a single active binding site: This dense packing of electrically resistive passivants perpendicular to the surface may limit the fill factor in pin PSCs. We identified ligands that bind two neighboring lead(II) ion (Pb2+) defect sites in a planar ligand orientation on the perovskite. We fabricated pin PSCs and report a certified quasi-steady state PCE of 26.15 and 24.74% for 0.05- and 1.04-square centimeter illuminated areas, respectively. The devices retain 95% of their initial PCE after 1200 hours of continuous 1 sun maximum power point operation at 65°C.

A Slotted Decellularized Osteochondral Scaffold With Layer-Specific Release of Stem Cell Differentiation Stimulators Enhances Cartilage and Bone Regeneration in Osteochondral Defects in a Rabbit Model.

BACKGROUND: Owing to the disappointing regenerative ability of osteochondral tissue, without treatment an osteochondral defect would progress to osteoarthritis. This situation motivates the need for new strategies to enhance the regeneration of osteochondral defects. PURPOSE: To develop a tissue-engineering scaffold by tethering bone morphogenetic protein 2 (BMP2) and transforming growth factor beta 3 (TGFß3) in a layer-specific manner on a slotted decellularized osteochondral matrix (SDOM) and to evaluate the efficacy of this scaffold for osteochondral regeneration. STUDY DESIGN: Controlled laboratory study. METHODS: Normal osteochondral tissue from the rabbit patellofemoral groove was sectioned into a slot shape and decellularized for fabricating an SDOM. The collagen-binding domain (CBD) was fused into the N-terminus of BMP2 or TGFß3 to synthesize 2 recombinant growth factors (GFs) (CBD-BMP2 or CBD-TGFß3), which were tethered to the bone layer and cartilage layer, respectively, of the SDOM to prepare a tissue-engineering scaffold (namely, CBD-GFs/SDOM). After examining the influence of the CBD-GFs/SDOM on the viability and layer-specific differentiation of bone marrow mesenchymal stem cells in vitro, we determined the regeneration potential of the CBD-GFs/SDOM on osteochondral regeneration in a rabbit model. A total of 72 New Zealand White rabbits with a cylindrical osteochondral defect in the patellofemoral groove were randomly assigned to 3 groups: defect only (control [CTL] group), defect patched with an SDOM (SDOM group), and defect patched with the CBD-GFs/SDOM (CBD-GFs/SDOM group). At 6 or 12 weeks postoperatively, the rabbits were euthanized to harvest the knee joint, which was then evaluated via gross observation, micro-computed tomography, histological staining, and mechanical testing. RESULTS: In vitro, the CBD-GFs/SDOM was noncytotoxic, showed high biomimetics with normal osteochondral tissue, was suitable for cell adhesion and growth, and had good layer-specific ability in inducing stem cell differentiation. Macroscopic images showed that the CBD-GFs/SDOM group had significantly better osteochondral regeneration than the CTL and SDOM groups had. Micro-computed tomography demonstrated that much more bony tissue was formed at the defect sites in the CBD-GFs/SDOM group compared with the defect sites in the CTL or SDOM group. Histological analysis showed that the CBD-GFs/SDOM group had a significant enhancement in osteochondral regeneration at 6 and 12 weeks postoperatively in comparison with the CTL or SDOM group. At 12 weeks postoperatively, the mechanical properties of reparative tissue were significantly better in the CBD-GFs/SDOM group than in the other groups. CONCLUSION: The CBD-GFs/SDOM is a promising scaffold for osteochondral regeneration. CLINICAL RELEVANCE: The findings of this study indicated that the CBD-GFs/SDOM is an excellent candidate for reconstructing osteochondral defects, which may be translated for clinical use in the future.

Engineering an enthesis-like graft for rotator cuff repair: An approach to fabricate highly biomimetic scaffold capable of zone-specifically releasing stem cell differentiation inducers.

Rotator cuff (RC) attaches to humerus across a triphasic yet continuous tissue zones (bone-fibrocartilage-tendon), termed "enthesis". Regrettably, rapid and functional enthesis regeneration is challenging after RC tear. The existing grafts bioengineered for RC repair are insufficient, as they were engineered by a scaffold that did not mimic normal enthesis in morphology, composition, and tensile property, meanwhile cannot simultaneously stimulate the formation of bone-fibrocartilage-tendon tissues. Herein, an optimized decellularization approach based on a vacuum aspiration device (VAD) was developed to fabricate a book-shaped decellularized enthesis matrix (O-BDEM). Then, three recombinant growth factors (CBP-GFs) capable of binding collagen were synthesized by fusing a collagen-binding peptide (CBP) into the N-terminal of BMP-2, TGF-ß3, or GDF-7, and zone-specifically tethered to the collagen of O-BDEM to fabricate a novel scaffold (CBP-GFs/O-BDEM) satisfying the above-mentioned requirements. After ensuring the low immunogenicity of CBP-GFs/O-BDEM by a novel single-cell mass cytometry in a mouse model, we interleaved urine-derived stem cell-sheets into this CBP-GFs/O-BDEM to bioengineer an enthesis-like graft. Its high-performance on regenerating enthesis was determined in a canine model. These findings indicate this CBP-GFs/O-BDEM may be an excellent scaffold for constructing enthesis-like graft to patch large/massive RC tears, and provide breakthroughs in fabricating graded interfacial tissue.

A novel graphene-based micro/nano architecture with high strength and conductivity inspired by multiple creatures.

In the long history of development and elimination, the creatures have derived a variety of exquisite structures and unique properties, typically natural nacre, marine mussel and Glycera to adapt to the environment and resist the predation of the enemy. Hence, inspired by the combination of special structures and properties of multiple creatures, a novel type of graphene-based micro/nano architecture was proposed, and the related bioinspired nanocomposites were fabricated, Polydopamine coated Graphene oxide/Nanocellulose/Polydopamine (P-GCP). Apart from replicating the layered structure of natural nacre, P-GCP also introduced copper ions and polydopamine to simulate the hardening mechanism of the Glycera's jaw and the composition of adhesive proteins in mussels to further improve the tensile strength and conductivity of nanocomposites, respectively. The test results showed that the tensile strength of P-GCP reached 712.9 MPa, which was 5.3 times that of natural nacre. The conductivity of artificial nacre was as high as 207.6 S/cm, which was equivalent to that of reduced graphene oxide (rGO). Furthermore, the material exhibited outstanding electrical conductivity when it connected as wires in a circuit, demonstrating the practical application prospects in aerospace, supercapacitors, biomaterials, artificial bones and tissue engineering.

Sustained release of collagen-affinity SDF-1α from book-shaped acellular fibrocartilage scaffold enhanced bone-tendon healing in a rabbit model.

Rapid and functional bone-tendon (B-T) healing remains a difficulty in clinical practice. Tissue engineering has emerged as a promising strategy to address this problem. However, the majority of tissue engineering scaffolds are loaded with stem cells to enhance the regenerability in B-T healing, which is complicated and inconvenient for clinical application. Accordingly, developing a cell-free scaffold with chemotactic function and chondrogenic inducibility may be an effective approach. In this study, a collagen affinity peptide derived from the A3 domain of von Willebrand factor (a hemostasis factor) was fused into the C-terminal of a stromal cell-derived factor-1α (SDF-1α) to synthesize a recombinant SDF-1α capable of binding collagen and chemotactic activity. The recombinant SDF-1α was then tethered on the collagen fibers of a book-shaped acellular fibrocartilage scaffold (BAFS), thus fabricating a novel scaffold (C-SDF-1α/BAFS) with chemotactic function and chondrogenic inducibility. In vitro tests determined that this scaffold was noncytotoxic and biomimetic, could attract stem cells migrating to the scaffold using sustainably released C-SDF-1α, and inducedthe interacting stem cells down the chondrogenic lineage. In vivo, the C-SDF-1α/BAFS significantly enhanced the B-T healing in a rabbit partial patellectomy model, as shown by the larger cartilaginous metaplasia region, better fibrocartilage regeneration, additional bone formation, and improved biomechanical properties. Therefore, the findings of the study demonstrate that the C-SDF-1α/BAFS could potentially be applied for B-T healing.

Cell-Free Book-Shaped Decellularized Tendon Matrix Graft Capable of Controlled Release of BMP-12 to Improve Tendon Healing in a Rat Model.

BACKGROUND: Achilles tendon (AT) defects often occur in traumatic and chronic injuries. Currently, no graft can satisfactorily regenerate parallel tendinous tissue at the defect site to completely restore AT function. PURPOSE: To develop a cell-free functional graft by tethering bone morphogenetic protein 12 (BMP-12) on a book-shaped decellularized tendon matrix (BDTM) and to determine whether this graft is more beneficial for AT defect healing than an autograft. STUDY DESIGN: Controlled laboratory study. METHODS: Canine patellar tendon was sectioned into a book shape and decellularized to fabricate a BDTM. The collagen-binding domain (CBD) was fused into the N-terminus of BMP-12 to synthesize a recombinant BMP-12 (CBD-BMP-12), which was tethered to the BDTM to prepare a cell-free functional graft (CBD-BMP-12/BDTM). After its tensile resistance, tenogenic inducibility, and BMP-12 release dynamics were evaluated, the efficacy of the graft for tendon regeneration was determined in a rat model. A total of 140 mature male Sprague-Dawley rats underwent AT tenotomy. The defect was reconstructed with reversed AT (autograft group), native BMP-12 tethered to an intact decellularized tendon matrix (IDTM; NAT-BMP-12/IDTM group), native BMP-12 tethered to a BDTM (NAT-BMP-12/BDTM group), CBD-BMP-12 tethered on an IDTM (CBD-BMP-12/IDTM group), and CBD-BMP-12 tethered on a BDTM (CBD-BMP-12/BDTM group). The rats were sacrificed 4 or 8 weeks after surgery to harvest AT specimens. Six specimens from each group at each time point were used for histological evaluation; the remaining 8 specimens were used for biomechanical testing. RESULTS: In vitro CBD-BMP-12/BDTM was noncytotoxic, showed high biomimetics with native tendons, was suitable for cell adhesion and growth, and had superior tenogenic inducibility. In vivo the defective AT in the CBD-BMP-12/BDTM group regenerated more naturally than in the other groups, as indicated by more spindle-shaped fibroblasts embedded in a matrix of parallel fibers. The biomechanical properties of the regenerated AT in the CBD-BMP-12/BDTM group also increased more significantly than in the other groups. CONCLUSION: CBD-BMP-12/BDTM is more beneficial than autograft for healing AT defects in a rat model. CLINICAL RELEVANCE: The findings of this study demonstrate that CBD-BMP-12/BDTM can serve as a practical graft for reconstructing AT defects.

Application of Autogenous Urine-Derived Stem Cell Sheet Enhances Rotator Cuff Healing in a Canine Model.

BACKGROUND: A repaired rotator cuff (RC) often heals with interposed scar tissue, making repairs prone to failure. Urine-derived stem cells (USCs), with robust proliferation ability and multilineage differentiation, can be isolated from urine, avoiding invasive and painful surgical procedures for harvesting the cells. These advantages make it a novel cell source for autologous transplantation to enhance RC healing. HYPOTHESIS: Implantation of an autogenous USC sheet to the injury site will enhance RC healing. STUDY DESIGN: Controlled laboratory study. METHODS: USCs isolated from urine were cultured using ascorbic acid and transforming growth factor ß3 to form a cell sheet. Sixteen male mature beagles underwent bilateral shoulder surgery. The right shoulder underwent infraspinatus tendon (IT) insertion detachment and repair only, and the other was subjected to IT insertion detachment and repair, followed by autogenous USC sheet implantation. Among the animals, 3 received a Dil (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate)- labeled USC sheet implant in the right shoulder and were sacrificed at postoperative 6 weeks for cell tracking. The other animals were sacrificed at postoperative 12 weeks, and the IT-humerus complexes were harvested for gross observation, micro-computed tomography evaluation and histological analysis (n = 5), and mechanical testing (n = 8). Additionally, 13 unpaired canine cadaveric shoulders were included as native controls. RESULTS: Micro-computed tomography analysis showed that the USC sheet group had a significant increase in bone volume/total volume and trabecular thickness at the RC healing site when compared with the control group (P < .05 for all). Histologically, the Dil-labeled USC sheet was still visible at the RC healing site, which suggested that the implanted USCs remained viable at postoperative 6 weeks. Meanwhile, the healing interface in the USC sheet group regenerated significantly more enthesis-like tissue than did that of the control group (P < .05). Additionally, the healing interface in the USC sheet group presented a larger fibrocartilage area, more proteoglycan deposition, and higher collagen birefringence than did that of the control group (P < .05 for all). Biomechanically, the USC sheet group showed significantly higher failure load and stiffness versus the control group (P < .05 for all). CONCLUSION: A USC sheet was able to enhance RC healing in a canine model. CLINICAL RELEVANCE: The findings of the study showed that USC sheet implantation could serve as a practical application for RC healing.