Neurological recovery and neurogenesis by curcumin sustained-release system cross-linked with an acellular spinal cord scaffold in rat spinal cord injury: Targeting NLRP3 inflammasome pathway.

In the context of treating spinal cord injury (SCI), the modulation of inflammatory responses, and the creation of a suitable region for tissue regeneration may present a promising approach. This study aimed to evaluate the effects of curcumin (Cur)-loaded bovine serum albumin nanoparticles (Cur-BSA NPs) cross-linked with an acellular spinal cord scaffold (ASCS) on the functional recovery in a rat model of SCI. We developed an ASCS using chemical and physical methods. Cur-BSA, and blank (B-BSA) NPs were fabricated and cross-linked with ASCS via EDC-NHS, resulting in the production of Cur-ASCS and B-ASCS. We assessed the properties of scaffolds and NPs as well as their cross-links. Finally, using a male rat hemisection model of SCI, we investigated the consequences of the resulting scaffolds. The inflammatory markers, neuroregeneration, and functional recovery were evaluated. Our results showed that Cur was efficiently entrapped at the rate of 42% ± 1.3 in the NPs. Compared to B-ASCS, Cur-ASCS showed greater effectiveness in the promotion of motor recovery. The implantation of both scaffolds could increase the migration of neural stem cells (Nestin- and GFAP-positive cells) following SCI with the superiority of Cur-ASCS. Cur-ASCS was successful to regulate the gene expression and protein levels of NLRP3, ASC, and Casp1in the spinal cord lesion. Our results indicate that using ASCS can lead to the entrance of cells into the scaffold and promote neurogenesis. However, Cur-ASCS had greater effects in terms of inflammation relief and enhanced neurogenesis.

Tissue engineered periosteum: Fabrication of a gelatin basedtrilayer composite scaffold with biomimetic properties for enhanced bone healing.

The periosteum, a vascularized tissue membrane, is essential in bone regeneration following fractures and bone loss due to some other reasons, yet there exist several research gaps concerning its regeneration. These gaps encompass reduced cellular proliferation and bioactivity, potential toxicity, heightened stiffness of scaffold materials, unfavorable porosity, expensive materials and procedures, and suboptimal survivability or inappropriate degradation rates of the implanted materials. This research used an interdisciplinary approach by forming a new material fabricated through electrospinning for the proposed application as a layer-by-layer tissue-engineered periosteum (TEP). TEP comprises poly(ε-caprolactone) (PCL), PCL/gelatin/magnesium-doped zinc oxide (vascular layer), and gelatin/bioactive glass/COD liver oil (osteoconductive layer). These materials were selected for their diverse properties, when integrated into the scaffold formation, successfully mimic the characteristics of native periosteum. Scanning electron microscopy (SEM) was employed to confirm the trilayer structure of the scaffold and determine the average fiber diameter. In-vitro degradation and swelling studies demonstrated a uniform degradation rate that matches the typical recovery time of periosteum. The scaffold exhibited excellent mechanical properties comparable to natural periosteum. Furthermore, the sustained release kinetics of COD liver oil were observed in the trilayer scaffold. Cell culture results indicated that the three-dimensional topography of the scaffold promoted cell growth, proliferation, and attachment, confirming its non-toxicity, biocompatibility, and bioactivity. This study suggests that the fabricated scaffold holds promise as a potential artificial periosteum for treating periostitis and bone fractures.

Bionic Bilayer Scaffold for Synchronous Hyperthermia Therapy of Orthotopic Osteosarcoma and Osteochondral Regeneration.

Large osseous void, postsurgical neoplastic recurrence, and slow bone-cartilage repair rate raise an imperative need to develop functional scaffold in clinical osteosarcoma treatment. Herein, a bionic bilayer scaffold constituting croconaine dye-polyethylene glycol@sodium alginate hydrogel and poly(l-lactide)/hydroxyapatite polymer matrix is fabricated to simultaneously achieve a highly efficient killing of osteosarcoma and an accelerated osteochondral regeneration. First, biomimetic osteochondral structure along with adequate interfacial interaction of the bilayer scaffold provide a structural reinforcement for transverse osseointegration and osteochondral regeneration, as evidenced by upregulated specific expressions of collagen type-I, osteopontin, and runt-related transcription factor 2. Meanwhile, thermal ablation of the synthesized nanoparticles and mitochondrial dysfunction caused by continuously released hydroxyapatite induce residual tumor necrosis synergistically. To validate the capabilities of inhibiting tumor growth and promoting osteochondral regeneration of our proposed scaffold, a novel orthotopic osteosarcoma model simulating clinical treatment scenarios of bone tumors is established on rats. Based on amounts of in vitro and in vivo results, an effective killing of osteosarcoma and a suitable osteal-microenvironment modulation of such bionic bilayer composite scaffold are achieved, which provides insightful implications for photonic hyperthermia therapy against osteosarcoma and following osseous tissue regeneration.

Combined effect of Cerium oxide nanoparticles loaded scaffold and photobiomodulation therapy on pain and neuronal regeneration following spinal cord injury: an experimental study.

BACKGROUND: Spinal cord injury (SCI) remained one of the challenges to treat due to its complicated mechanisms. Photobiomodulation therapy (PBMT) accelerates neuronal regeneration. Cerium oxide nanoparticles (CeONPs) also eliminate free radicals in the environment. The present study aims to introduce a combined treatment method of making PCL scaffolds as microenvironments, seeded with CeONPs and the PBMT technique for SCI treatment. METHODS: The surgical hemi-section was used to induce SCI. Immediately after the SCI induction, the scaffold (Sc) was loaded with CeONPs implanted. PBMT began 30 min after SCI induction and lasted for up to 4 weeks. Fifty-six male rats were randomly divided into seven groups. Glial fibrillary acidic protein (GFAP) (an astrocyte marker), Connexin 43 (Con43) (a member of the gap junction), and gap junctions (GJ) (a marker for the transfer of ions and small molecules) expressions were evaluated. The behavioral evaluation was performed by BBB, Acetone, Von Frey, and radiant heat tests. RESULT: The SC + Nano + PBMT group exhibited the most remarkable recovery outcomes. Thermal hyperalgesia responses were mitigated, with the combined approach displaying the most effective relief. Mechanical allodynia and cold allodynia responses were also attenuated by treatments, demonstrating potential pain management benefits. CONCLUSION: These findings highlight the potential of PBMT, combined with CeONPs-loaded scaffolds, in promoting functional motor recovery and alleviating pain-related responses following SCI. The study underscores the intricate interplay between various interventions and their cumulative effects, informing future research directions for enhancing neural repair and pain management strategies in SCI contexts.

Bio-integrated scaffold facilitates large bone regeneration dominated by endochondral ossification.

Repair of large bone defects caused by severe trauma, non-union fractures, or tumor resection remains challenging because of limited regenerative ability. Typically, these defects heal through mixed routines, including intramembranous ossification (IMO) and endochondral ossification (ECO), with ECO considered more efficient. Current strategies to promote large bone healing via ECO are unstable and require high-dose growth factors or complex cell therapy that cause side effects and raise expense while providing only limited benefit. Herein, we report a bio-integrated scaffold capable of initiating an early hypoxia microenvironment with controllable release of low-dose recombinant bone morphogenetic protein-2 (rhBMP-2), aiming to induce ECO-dominated repair. Specifically, we apply a mesoporous structure to accelerate iron chelation, this promoting early chondrogenesis via deferoxamine (DFO)-induced hypoxia-inducible factor-1α (HIF-1α). Through the delicate segmentation of click-crosslinked PEGylated Poly (glycerol sebacate) (PEGS) layers, we achieve programmed release of low-dose rhBMP-2, which can facilitate cartilage-to-bone transformation while reducing side effect risks. We demonstrate this system can strengthen the ECO healing and convert mixed or mixed or IMO-guided routes to ECO-dominated approach in large-size models with clinical relevance. Collectively, these findings demonstrate a biomaterial-based strategy for driving ECO-dominated healing, paving a promising pave towards its clinical use in addressing large bone defects.

[Development of Functional Compounds Using Chemically Unstable Compounds Obtained from Medicinal Plants].

Sulfur- or nitrogen-containing compounds from medicinal plants exhibit various biological activities such as anticancer potential. Developing efficient strategies to isolate or synthesize these compounds or their derivatives is a remarkable achievement. We have isolated several sulfur-containing compounds such as tetrahydro-2H-difuro[3,2-b:2',3'-c]furan-5(5aH)-one derivatives from Allium plants. We have devised a unique approach for the rapid preparation of thiopyranones using the regioselective sequential double Diels-Alder reaction; we used a naturally-occurring chemically-unstable intermediate such as thioacrolein, which is produced from allicin, a major component in garlic. The cytotoxicity of the synthetic thiopyranones against cancer stem cells (CSCs) was equal to or higher than that of (Z)-ajoene, the reference compound.

In vitro assessment of Momordica charantia/Hypericum perforatum oils loaded PCL/Collagen fibers: Novel scaffold for tissue engineering.

The research on tissue engineering applications has been progressing to manufacture ideal tissue scaffold biomaterials. In this study, a double-layered electrospun biofiber scaffold biomaterial including Polycaprolactone (PCL)/Collagen (COL) fibrous inner layer and PCL/ Momordica charantia (MC) and Hypericum perforatum (HP) oils fibrous outer layer was developed to manufacture a functional, novel tissue scaffold with the advantageous mechanical and biological properties. The main approach was to combine the natural perspective using medicinal oils with an engineering point of view to fabricate a potential functional scaffold for tissue engineering. Medicinal plants MC and HP are rich in functional oils and incorporation of them in a tissue scaffold will unveil their potential to augment both new tissue formation and wound healing. In this study, a novel double-layered scaffold prototype was fabricated using electrospinning technique with two PCL fiber layers, first is composed of collagen, and second is composed of oils extracted from medicinal plants. Initially, the composition of plant oils was analyzed. Thereafter the biofiber scaffold layers were fabricated and were evaluated in terms of morphology, physicochemistry, thermal and mechanical features, wettability, in vitro bio-degradability. Double-layered scaffold prototype was further analyzed in terms of in vitro biocompatibility and antibacterial effect. The medicinal oils blend provided antioxidant and antibacterial properties to the novel PCL/Oils layer. The results signify that inner PCL/COL layer exhibited advanced biodegradability of 8.5% compared to PCL and enhanced wettability with 11.7° contact angle. Strength of scaffold prototype was 5.98 N/mm2 thanks to the elastic PCL fibrous matrix. The double-layered functional biofiber scaffold enabled 92% viability after 72 h contact with fibroblast cells and furthermore provided feasible attachment sites for the cells. The functional scaffold prototype's noteworthy mechanical, chemical, and biological features enable it to be suggested as a different novel biomaterial with the potential to be utilized in tissue engineering applications.

3D bioprinting of Salvianolic acid B-sodium alginate-gelatin skin scaffolds promotes diabetic wound repair via antioxidant, anti-inflammatory, and proangiogenic effects.

In patients with diabetic wounds, wound healing is impaired due to the presence of persistent oxidative stress, an altered inflammatory response, and impaired angiogenesis and epithelization. Salvianolic acid B (SAB), which is derived from the Chinese medicinal plant Salvia miltiorrhiza, has been found to exhibit antioxidant, anti-inflammatory, and proangiogenic effects. Previous studies have used 3D bioprinting technology incorporating sodium alginate (SA) and gelatin (Gel) as basic biomaterials to successfully produce artificial skin. In the current study, 3D bioprinting technology was used to incorporate SAB into SA-Gel to form a novel SAB-SA-Gel composite porous scaffold. The morphological characteristics, physicochemical characteristics, biocompatibility, and SAB release profile of the SAB-SA-Gel scaffolds were evaluated in vitro. In addition, the antioxidant, anti-inflammatory, and proangiogenic abilities of the SAB-SA-Gel scaffolds were evaluated in cells and in a rat model. Analysis demonstrated that 1.0 wt% (the percentage of SAB in the total weight of the solution containing SA and Gel) SAB-SA-Gel scaffolds had strong antioxidant, anti-inflammatory, and proangiogenic properties both in cells and in the rat model. The 1.0% SAB-SA-Gel scaffold reduced the expression of tumor necrosis factor-α, interleukin-6, and interluekin-1ß and increased the expression of transforming growth factor-ß. In addition, this scaffold removed excessive reactive oxygen species by increasing the expression of superoxide dismutase, thereby protecting fibroblasts from injury. The scaffold increased the expression of vascular endothelial growth factor and platelet/endothelial cell adhesion molecule-1, accelerated granulation tissue regeneration and collagen deposition, and promoted wound healing. These findings suggest that this innovative scaffold may have promise as a simple and efficient approach to managing diabetic wound repair.

Porous scaffold hydroxyapatite from sand lobster shells (Panulirus homarus) using polyethylene oxide/chitosan as polymeric porogen for bone tissue engineering.

The hydroxyapatite (HAp; Ca10 (PO4 )6 (OH)2 )) has good biocompatibility, bioactivity, and osteoconductivity as a bone implant because the main inorganic mineral of human bone is HAp. The use of scaffold HAp from biogenic resources that contain high calcium and polymer as a pore forming agent to support bone growth is a longstanding area of interest. In this study, porous scaffolds based on HAp were synthesized from sand lobster (SL; Panulirus homarus) shells as a source of calcium using the porogen leaching method with polyethylene oxide (PEO) and chitosan (Chs) as polymeric porogen. The present study aims to synthesize HAp derived from SL shells and evaluate the effect variations of PEO on the physicochemical properties of the scaffold and cytotoxicity in cell viability assay. Briefly, the SL shell powder was calcinated with temperature variations of 600°C, 800°C, and 1000°C for 6 h. Based on the characterization, it was shown that 1000°C was the optimum calcination temperature for SL shells to synthesize HAp using the precipitation method. The characterization results of HAp using energy dispersive x-ray (EDX) revealed that the molar ratio of Ca/P was 1.67. The Fourier transform infrared (FTIR) and x-ray diffractometer (XRD) spectral patterns indicated that HAp had been successfully synthesized with minor ß-tricalcium phosphate (ß-TCP), a calcium phosphate with high biocompatibility. Porous scaffolds were synthesized by varying the concentration of PEO at 0, 5, 10, and 15 wt %. Physicochemical analysis revealed that a higher concentration of PEO affected decreased crystallinity and compressive strength, but on the other hand, the porosity and pore sizes increased. Based on the physicochemical analysis, the synthesized porous scaffold showed that HAp/PEO/Chs 15 wt % had the most potential as a scaffold for biomedical applications. MTT Assay, after 24 h incubation, revealed that the scaffold was safe for use at low concentrations on the MC3T3E1 osteoblast cells, with a percentage of cell viability of 83.23 ± 3.18% at 23.4375 µg/mL. Although the cell viability decreased at higher concentrations, the HAp/PEO/Chs 15 wt % scaffold was cytocompatible with the cells. Thus, in the present study, HAp/PEO/Chs 15 wt % was the best scaffold based on pore structure, chemical composition, mechanical and crystalographic properties and cell viability.

Articular Cartilage Reconstruction with Hyaluronate-Based Scaffold Significantly Decreases Pain and Improves Patient's Functioning.

Articular cartilage lesions negatively affect patients' well-being, causing severe pain and significantly limiting functioning. The purpose of this study was to evaluate the effectiveness of a one-stage reconstruction, performed arthroscopically using a hyaluronate-based scaffold. Pain reduction and functional improvement were assessed. The study also evaluated if postoperative vitamin D supplementation and rehabilitation protocol impact obtained outcomes. A group of 29 patients was included in a retrospective study. All the participants underwent arthroscopic reconstruction of osteochondral lesions using hyaluronate-based scaffolds. The study group used standard questionnaires to self-assess their condition before surgery and at the time of completion. Despite the aforementioned, all the participants fulfilled two original questionnaires on postoperative rehabilitation and vitamin D supplementation. Significant pain reduction (mean NRS 1.83 vs. 7.21, p < 0.0001) and functional improvement (mean Lysholm score 82.38 vs. 40.38, p < 0.0001; mean OKS 40.2 vs. 23.1, p < 0.0001) were found. No differences in pain reduction and functional improvement were seen between genders. The impact of post-operative rehabilitation and vitamin D supplementation on clinical outcomes was found to be statistically nonsignificant. The results obtained in this study clearly confirm the effectiveness of osteochondral reconstruction using hyaluronate-based scaffolds. The outcomes were equally favorable, regardless of postoperative rehabilitation and vitamin D supplementation.

Lead optimization of Allium sativum L. compounds for PTP1B inhibition in diabetes treatment: in silico molecular docking and dynamics simulation.

Protein tyrosine phosphatase 1B (PTP1B) has been identified as a promising drug target for the development of diabetes medications via an inhibition mechanism. Using a computational approach, this study investigates the binding mechanism of lead optimized natural compounds from Allium sativum against the human PTP1B. The molecular docking, induced-fit docking, and binding free energy calculations were analyzed using Schrödinger Suite 2021-2. MD simulation, and gene enrichment analysis was achieved via the Desmond module of Schrödinger to identify best compounds as inhibitors against PTP1B in diabetes management. The docking scores of the lead optimized compounds were good; 5280443_121 from apigenin had the best binding score of -9.345 kcal/mol, followed by 5280443_129 with a binding score of -9.200 kcal/mol, and 5280863_177 from kaempferol had a binding score of -8.528 kcal/mol, followed by 5280863_462 with a binding score of -8.338 kcal/mol. The top two lead optimized compounds, docked better than the standard PTP1B inhibitor (-7.155 kcal/mol), suggesting them as potent inhibitors than the standard PTP1B inhibitor. The outcomes of the induced-fit docking were consistent with the increased binding affinity used in the Glide computation of the five conformed poses between the derivatives (5280443_121, 5280443_129, 5280863_177, and 5280863_462) and the protein (PTP1B). Based on the binding fee energies (MM-GBSA), the lead optimized compounds from kaempferol exhibited more stability than those from apigenin. In the pharmacophore development, all the models exhibit good results across the different metrics. The best performing model with five of five matches on a 1.34 and 1.33 phase score was DDRRR_1, DDRRR_2, and DDDRR_1. The average BEDROC value (= 160.9) was 1, while the average EF 1% value across all models was 101. There were no substantial conformational modifications during the MD simulation process, indicating that the apigenin derivatives (5280443_121) was stable in the protein's active site in 100 ns. IGF1R, EGFR, INSR, PTPN1, SRC, JAK2, GRB2, BCAR1, and IRS1 are among the 11 potential targets found in the protein-protein interaction (PPI) of A. sativum against PTP1B that may be important in A. sativum's defense against PTP1B. Sixty-four (64) pathways were found by KEGG pathway enrichment analysis to be potentially involved in the anti-PTP1B of A. sativum. Consequently, data obtained indicates the effectiveness of the in silico studies in identifying potential lead compounds in A. sativum against PTP1B target.Communicated by Ramaswamy H. Sarma.

Discovery of inhibitors of protein tyrosine phosphatase 1B contained in a natural products library from Mexican medicinal plants and fungi using a combination of enzymatic and in silico methods*.

This work aimed to discover protein tyrosine phosphatase 1B (PTP1B) inhibitors from a small molecule library of natural products (NPs) derived from selected Mexican medicinal plants and fungi to find new hits for developing antidiabetic drugs. The products showing similar IC50 values to ursolic acid (UA) (positive control, IC50 = 26.5) were considered hits. These compounds were canophyllol (1), 5-O-(ß-D-glucopyranosyl)-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin (2), 3,4-dimethoxy-2,5-phenanthrenediol (3), masticadienonic acid (4), 4',5,6-trihydroxy-3',7-dimethoxyflavone (5), E/Z vermelhotin (6), tajixanthone hydrate (7), quercetin-3-O-(6″-benzoyl)-ß-D-galactoside (8), lichexanthone (9), melianodiol (10), and confusarin (11). According to the double-reciprocal plots, 1 was a non-competitive inhibitor, 3 a mixed-type, and 6 competitive. The chemical space analysis of the hits (IC50 < 100 µM) and compounds possessing activity (IC50 in the range of 100-1,000 µM) with the BIOFACQUIM library indicated that the active molecules are chemically diverse, covering most of the known Mexican NPs' chemical space. Finally, a structure-activity similarity (SAS) map was built using the Tanimoto similarity index and PTP1B absolute inhibitory activity, which allows the identification of seven scaffold hops, namely, compounds 3, 5, 6, 7, 8, 9, and 11. Canophyllol (1), on the other hand, is a true analog of UA since it is an SAR continuous zone of the SAS map.

Electrospun Scaffolds as Antimicrobial Herbal Extract Delivery Vehicles for Wound Healing.

Herbal extracts have been used in traditional remedies since the earliest myths. They have excellent antimicrobial, anti-inflammatory, and antioxidant activities owing to various bioactive components in their structure. However, due to their inability to reach a target and low biostability, their use with a delivery vehicle has come into prominence. For this purpose, electrospun nanofibrous scaffolds have been widely preferred for the delivery and release of antimicrobial herbal extracts due to the flexibility and operational versatility of the electrospinning technique. Herein, we briefly reviewed the electrospun nanofibrous scaffolds as delivery systems for herbal extracts with a particular focus on the preclinical studies for wound-healing applications that have been published in the last five years. We also discussed the indirect effects of herbal extracts on wound healing by altering the characteristics of electrospun mats.

Biomimetic Cardiac Fibrotic Model for Antifibrotic Drug Screening.

Cardiac fibrosis is characterized by pathological proliferation and activation of cardiac fibroblasts to myofibroblasts. Inhibition and reverse of transdifferentiation of cardiac fibroblasts to myofibroblasts is a potential strategy for cardiac fibrosis. Despite substantial progress, more effort is needed to discover effective drugs to improve and reverse cardiac fibrosis. The main reason for the slow development of antifibrotic drugs is that the traditional polystyrene culture platform does not recapitulate the microenvironment where cells reside in tissues. In this study, we propose an in vitro cardiac fibrotic model by seeding electrospun yarn scaffolds with cardiac fibroblasts. Our results show that yarn scaffolds allow three-dimensional growth of cardiac fibroblasts, promote extracellular matrix (ECM) deposition, and induce the transdifferentiation of cardiac fibroblasts to myofibroblasts. Exogenous transforming growth factor-ß1 further promotes cardiac fibroblast activation and ECM deposition, which makes it a suitable fibrotic model to predict the antifibrotic potential of drugs. By using this platform, we demonstrate that both Honokiol (HKL) and Pirfenidone (PFD) show potential in antifibrosis to some extent. HKL is more efficient in antifibrosis than PFD as revealed by biochemical composition, gene, and molecular analyses as well as histological and biomechanical analysis. The electrospun yarn scaffold provides a novel platform for constructing in vitro fibrotic models to study cardiac fibrosis and to predict the antifibrotic efficacy of novel drugs.

A multifunctional nano-hydroxyapatite/MXene scaffold for the photothermal/dynamic treatment of bone tumours and simultaneous tissue regeneration.

After resection of bone tumour, the risk of cancer recurrence and numerous bone defects continues to threaten the health of patients. To overcome the challenge, we developed a novel multifunctional scaffold material consisting mainly of nano-hydroxyapatite particles (n-HA), MXene nanosheets and g-C3N4 to prevent tumour recurrence and promote bone formation. N-HA has the potential to restrict the growth of osteosarcoma cells, and the combination of MXene and g-C3N4 enables the scaffolds to produce photodynamic and photothermal effects simultaneously under near infrared (NIR) irradiation. Surprisingly, n-HA can further enhance the synergistic anti-tumour function of photodynamic and photothermal, and the scaffolds can eradicate osteosarcoma cells in only 10 min at a mild temperature of 45 ℃. Moreover, the scaffold exhibit exceptional cytocompatibility and possesses the capacity to induce osteogenic differentiation of bone marrow mesenchymal stem cells. Therefore, this multifunctional scaffold can not only inhibits the proliferation of bone tumour cells and rapidly eradicate bone tumour through NIR irradiation, but also enhances osteogenic activity. This promising measure can be used to treat tissue damage after bone tumour resection.

Combination of human platelet lysate and 3D gelatin scaffolds to enhance osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells.

Bone disorders are major health issues requiring specialized care; however, the traditional bone grafting method had several limitations. Thus, bone tissue engineering has become a potential alternative. In therapeutic treatments, using fetal bovine serum (FBS) as a culture supplement may result in the risk of contamination and host immunological response; therefore, human platelet lysate (hPL) has been considered a viable alternative source. This study attempted to compare the effectiveness and safety of different culture supplements, either FBS or hPL, on the osteoblastic differentiation potential of mesenchymal stem cells derived from human amniotic fluid (hAF-MSCs) under a three-dimensional gelatin scaffold. The results indicate that hAF-MSCs have the potential to be used in clinical applications as they meet the criteria for mesenchymal stem cells based on their morphology, the expression of a particular surface antigen, their proliferation ability, and their capacity for multipotent differentiation. After evaluation by MTT and Alamar blue proliferation assay, 10% of hPL was selected. The osteogenic differentiation of hAF-MSCs under three-dimensional gelatin scaffold using osteogenic-induced media supplemented with hPL was achievable and markedly stimulated osteoblast differentiation. Moreover, the expressions of osteoblastogenic related genes, including OCN, ALP, and COL1A1, exhibited the highest degree of expression under hPL-supplemented circumstances when compared with the control and the FBS-supplemented group. The induced cells under hPL-supplemented conditions also presented the highest ALP activity level and the greatest degree of calcium accumulation. These outcomes would indicate that hPL is a suitable substitute for animal derived serum. Importantly, osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells using hPL-supplemented media and three-dimensional scaffolds may open the door to developing an alternative construct for repairing bone defects.

A tumor-microenvironment-activated nanoplatform of modified SnFe2O4 nanozyme in scaffold for enhanced PTT/PDT tumor therapy.

Phototherapy has attracted widespread attention for cancer treatment due to its noninvasiveness and high selectivity. However, severe hypoxia, overexpressed glutathione and high levels of hydrogen peroxide (H2O2) of tumor microenvironment limit the antitumor efficiency of phototherapy. Herein, inspired by the specific response of nanozymes to the tumor microenvironment, a simple and versatile nanozyme-mediated synergistic dual phototherapy nanoplatform is constructed. In this study, tin ferrite (SnFe2O4, SFO) nanozyme as a photosensitizer was surface modified with polydopamine (denoted as P-SFO) and incorporated into poly(l-lactide) to fabricate an antitumor scaffold fabricated by selective laser sintering. On one hand, SFO nanozyme could act as a photoabsorber to convert light energy into heat for photothermal therapy (PTT). On the other hand, it played a role of photosensitizer in transferring the photon energy to generate reactive oxygen species (ROS) for photodynamic therapy (PDT). Importantly, its multivalent metal ions redox couples would decompose H2O2 into O2 for enhancing O2-dependent PDT and consume glutathione to relieve antioxidant capability of the tumors. Besides, polydopamine as a photothermal conversion agent further enhanced the photothermal performance of SFO. The results revealed the PLLA/P-SFO scaffold possessed a photothermal conversion efficiency of 43.52% for PTT and a high ROS generation capacity of highly toxic ·O2- and ·OH for PDT. Consequently, the scaffold displayed a prominent phototherapeutic effect with antitumor rate of 96.3%. In addition, the PLLA/P-SFO scaffolds possessed good biocompatibility for cell growth. These advantages endow PLLA/P-SFO scaffold with extensive applications in biomedical fields and opened up new avenue towards nanozyme-mediated synergistic phototherapy.

Development of a rat model of lymphedema and the implantation of a collagen-based medical device for therapeutic intervention.

Secondary lymphedema is a common condition among cancer survivors, and treatment strategies to prevent or treat lymphedema are in high demand. The development of novel strategies to diagnose or treat lymphedema would benefit from a robust experimental animal model of secondary lymphedema. The purpose of this methods paper is to describe and summarize our experience in developing and characterizing a rat hindlimb model of lymphedema. Here we describe a protocol to induce secondary lymphedema that takes advantage of micro computed tomography imaging for limb volume measurements and visualization of lymph drainage with near infrared imaging. To demonstrate the utility of this preclinical model for studying the therapeutic benefit of novel devices, we apply this animal model to test the efficacy of a biomaterials-based implantable medical device.

Osteogenic differentiation of adipose-derived canine mesenchymal stem cells seeded in porous calcium-phosphate scaffolds.

Introduction: Engineered bone graft substitutes are a promising alternative and supplement to autologous bone grafts as treatments for bone healing impairment. Advances in human medicine extend an invitation to pursue these biomimetic strategies in animal patients, substantiated by the theory that specialized scaffolds, multipotent cells, and biological cues may be combined into a bioactive implant intended for the enhancement of tissue regeneration. Methods: This proof-of-concept study was designed to evaluate and validate the feasibility of beta-tricalcium phosphate foam scaffolds seeded with canine mesenchymal stem cells derived from adipose tissue. Cell-inoculated samples and sham controls were cultured statically for 72 hours in complete growth medium to evaluate seeding capacity, while a subset of loaded scaffolds was further induced with osteogenic culture medium for 21 days. Produced implants were characterized and validated with a combination of immunofluorescence and reflection confocal microscopy, scanning electron microscopy, and polymerase chain reaction to confirm osteogenic differentiation in tridimensional-induced samples. Results: After 72 hours of culture, all inoculated scaffolds presented widespread yet heterogeneous surface seeding, distinctively congregating stem cells around pore openings. Furthermore, at 21 days of osteogenic culture conditions, robust osteoblastic differentiation of the seeded cells was confirmed by the change of cell morphology and evident deposition of extra-cellular matrix, accompanied by mineralization and scaffold remodeling; furthermore, all induced cell-loaded implants lost specific stemness immunophenotype expression and simultaneously upregulated genomic expression of osteogenic genes Osterix and Ostecalcin. Conclusions: ß-TCP bio-ceramic foam scaffolds proved to be suitable carriers and hosts of canine adipose-derived MSCs, promoting not only surface attachment and proliferation, but also demonstrating strong in-vitro osteogenic potential. Although this research provides satisfactory in-vitro validation for the conceptualization and feasibility of a canine bio-active bone implant, further testing such as patient safety, large-scale reproducibility, and quality assessment are needed for regulatory compliance in future commercial clinical applications.

Micronutrient optimization for tissue engineered articular cartilage production of type II collagen.

Tissue Engineering of cartilage has been hampered by the inability of engineered tissue to express native levels of type II collagen in vitro. Inadequate levels of type II collagen are, in part, due to a failure to recapitulate the physiological environment in culture. In this study, we engineered primary rabbit chondrocytes to express a secreted reporter, Gaussia Luciferase, driven by the type II collagen promoter, and applied a Design of Experiments approach to assess chondrogenic differentiation in micronutrient-supplemented medium. Using a Response Surface Model, 240 combinations of micronutrients absent in standard chondrogenic differentiation medium, were screened and assessed for type II collagen promoter-driven Gaussia luciferase expression. While the target of this study was to establish a combination of all micronutrients, alpha-linolenic acid, copper, cobalt, chromium, manganese, molybdenum, vitamins A, E, D and B7 were all found to have a significant effect on type II collagen promoter activity. Five conditions containing all micronutrients predicted to produce the greatest luciferase expression were selected for further study. Validation of these conditions in 3D aggregates identified an optimal condition for type II collagen promoter activity. Engineered cartilage grown in this condition, showed a 170% increase in type II collagen expression (Day 22 Luminescence) and in Young's tensile modulus compared to engineered cartilage in basal media alone.Collagen cross-linking analysis confirmed formation of type II-type II collagen and type II-type IX collagen cross-linked heteropolymeric fibrils, characteristic of mature native cartilage. Combining a Design of Experiments approach and secreted reporter cells in 3D aggregate culture enabled a high-throughput platform that can be used to identify more optimal physiological culture parameters for chondrogenesis.