Osteoregenerative Potential of 3D-Printed Poly ε-Caprolactone Tissue Scaffolds In Vitro Using Minimally Manipulative Expansion of Primary Human Bone Marrow Stem Cells.

The repair of orthopedic and maxillofacial defects in modern medicine currently relies heavily on the use of autograft, allograft, void fillers, or other structural material composites. This study examines the in vitro osteo regenerative potential of polycaprolactone (PCL) tissue scaffolding, fabricated via a three-dimensional (3D) additive manufacturing technology, i.e., a pneumatic micro extrusion (PME) process. The objectives of this study were: (i) To examine the innate osteoinductive and osteoconductive potential of 3D-printed PCL tissue scaffolding and (ii) To perform a direct in vitro comparison of 3D-printed PCL scaffolding with allograft Allowash® cancellous bone cubes with regards to cell-scaffold interactions and biocompatibility with three primary human bone marrow (hBM) stem cell lines. This study specifically examined cell survival, cell integration, intra-scaffold cell proliferation, and differentiation of progenitor cells to investigate the potential of 3D-printed PCL scaffolds as an alternative to allograft bone material for the repair of orthopedic injuries. We found that mechanically robust PCL bone scaffolds can be fabricated via the PME process and the resulting material did not elicit detectable cytotoxicity. When the widely used osteogenic model SAOS-2 was cultured in PCL extract medium, no detectable effect was observed on cell viability or proliferation with multiple test groups showing viability ranges of 92.2% to 100% relative to a control group with a standard deviation of ±10%. In addition, we found that the honeycomb infill pattern of the 3D-printed PCL scaffold allowed for superior mesenchymal stem-cell integration, proliferation, and biomass increase. When healthy and active primary hBM cell lines, having documented in vitro growth rates with doubling times of 23.9, 24.67, and 30.94 h, were cultured directly into 3D-printed PCL scaffolds, impressive biomass increase values were observed. It was found that the PCL scaffolding material allowed for biomass increase values of 17.17%, 17.14%, and 18.18%, compared to values of 4.29% for allograph material cultured under identical parameters. It was also found that the honeycomb scaffold infill pattern was superior to the cubic and rectangular matrix structures, and provided a superior microenvironment for osteogenic and hematopoietic progenitor cell activity and auto-differentiation of primary hBM stem cells. Histological and immunohistochemical studies performed in this work confirmed the regenerative potential of PCL matrices in the orthopedic setting by displaying the integration, self-organization, and auto-differentiation of hBM progenitor cells within the matrix. Differentiation products including mineralization, self-organizing "proto-osteon" structures, and in vitro erythropoiesis were observed in conjunction with the documented expression of expected bone marrow differentiative markers including CD-99 (>70%), CD-71 (>60%), and CD-61 (>5%). All of the studies were conducted without the addition of any exogenous chemical or hormonal stimulation and exclusively utilized the abiotic and inert material polycaprolactone; setting this work apart from the vast majority of contemporary investigations into synthetic bone scaffold fabrication In summary, this study demonstrates the unique clinical potential of 3D-printed PCL scaffolds for stem cell expansion and incorporation into advanced microstructures created via PME manufacturing to generate a physiologically inert temporary bony defect graft with significant autograft features for enhanced end-stage healing.

Engineered Macrophages-Based uPA-Scavenger Load Gemcitabine to Prompt Robust Treating Cancer Metastasis.

The majority of cancer patients die of metastasis rather than primary tumors, and most patients may have already completed the cryptic metastatic process at the time of diagnosis, making them intractable for therapeutic intervention. The urokinase-type plasminogen activator (uPA) system is proved to drive cancer metastasis. However, current blocking agents such as uPA inhibitors or antibodies are far from satisfactory due to poor pharmacokinetics and especially have to face multiplex mechanisms of metastasis. Herein, an effective strategy is proposed to develop a uPA-scavenger macrophage (uPAR-MΦ), followed by loading chemotherapeutics with nanoparticles (GEM@PLGA) to confront cancer metastasis. Interestingly, significant elimination of uPA by uPAR-MΦ is demonstrated by transwell analysis on tumor cells in vitro and enzyme-linked immunosorbent assay detection in peripheral blood of mice with metastatic tumors, contributing to significant inhibition of migration of tumor cells and occurrence of metastatic tumor lesions in mice. Moreover, uPAR-MΦ loaded with GEM@PLGA shows a robust antimetastasis effect and significantly prolonged survival in 4T1-tumor-bearing mice models. This work provides a novel living drug platform for realizing a potent treatment strategy to patients suffering from cancer metastasis, which can be further expanded to handle other tumor metastasis markers mediating cancer metastasis.

Regeneration of Bone Defects in a Rabbit Femoral Osteonecrosis Model Using 3D-Printed Poly (Epsilon-Caprolactone)/Nanoparticulate Willemite Composite Scaffolds.

Steroid-associated osteonecrosis (SAON) is a chronic disease that leads to the destruction and collapse of bone near the joint that is subjected to weight bearing, ultimately resulting in a loss of hip and knee function. Zn2+ ions, as an essential trace element, have functional roles in improving the immunophysiological cellular environment, accelerating bone regeneration, and inhibiting biofilm formation. In this study, we reconstruct SAON lesions with a three-dimensional (3D)-a printed composite made of poly (epsilon-caprolactone) (PCL) and nanoparticulate Willemite (npW). Rabbit bone marrow stem cells were used to evaluate the cytocompatibility and osteogenic differentiation capability of the PCL/npW composite scaffolds. The 2-month bone regeneration was assessed by a Micro-computed tomography (micro-CT) scan and the expression of bone regeneration proteins by Western blot. Compared with the neat PCL group, PCL/npW scaffolds exhibited significantly increased cytocompatibility and osteogenic activity. This finding reveals a new concept for the design of a 3D-printed PCL/npW composite-based bone substitute for the early treatment of osteonecrosis defects.

Inhibition of A549 Lung Cancer Cell Migration and Invasion by Ent-Caprolactin C via the Suppression of Transforming Growth Factor-ß-Induced Epithelial-Mesenchymal Transition.

The epithelial-mesenchymal transition (EMT) of cancer cells is a crucial process in cancer cell metastasis. An Aquimarina sp. MC085 extract was found to inhibit A549 human lung cancer cell invasion, and caprolactin C (1), a new natural product, α-amino-ε-caprolactam linked to 3-methyl butanoic acid, was purified through bioactivity-guided isolation of the extract. Furthermore, its enantiomeric compound, ent-caprolactin C (2), was synthesized. Both 1 and 2 inhibited the invasion and γ-irradiation-induced migration of A549 cells. In transforming growth factor-ß (TGF-ß)-treated A549 cells, 2 inhibited the phosphorylation of Smad2/3 and suppressed the EMT cell marker proteins (N-cadherin, ß-catenin, and vimentin), as well as the related messenger ribonucleic acid expression (N-cadherin, matrix metalloproteinase-9, Snail, and vimentin), while compound 1 did not suppress Smad2/3 phosphorylation and the expression of EMT cell markers. Therefore, compound 2 could be a potential candidate for antimetastatic agent development, because it suppresses TGF-ß-induced EMT.

α-Hydroxyisocaproic Acid Decreases Protein Synthesis but Attenuates TNFα/IFNγ Co-Exposure-Induced Protein Degradation and Myotube Atrophy via Suppression of iNOS and IL-6 in Murine C2C12 Myotube.

There is ongoing debate as to whether or not α-hydroxyisocaproic acid (HICA) positively regulates skeletal muscle protein synthesis resulting in the gain or maintenance of skeletal muscle. We investigated the effects of HICA on mouse C2C12 myotubes under normal conditions and during cachexia induced by co-exposure to TNFα and IFNγ. The phosphorylation of AMPK or ERK1/2 was significantly altered 30 min after HICA treatment under normal conditions. The basal protein synthesis rates measured by a deuterium-labeling method were significantly lowered by the HICA treatment under normal and cachexic conditions. Conversely, myotube atrophy induced by TNFα/IFNγ co-exposure was significantly improved by the HICA pretreatment, and this improvement was accompanied by the inhibition of iNOS expression and IL-6 production. Moreover, HICA also suppressed the TNFα/IFNγ co-exposure-induced secretion of 3-methylhistidine. These results demonstrated that HICA decreases basal protein synthesis under normal or cachexic conditions; however, HICA might attenuate skeletal muscle atrophy via maintaining a low level of protein degradation under cachexic conditions.

α-amyrin-loaded nanocapsules produce selective cytotoxic activity in leukemic cells.

INTRODUCTION: Amyrins are triterpenes that have attractive pharmacological potential; however, their low water solubility and erratic stomach absorption hinders their use as a drug. The aim of this paper was to develop a novel α-amyrin-loaded nanocapsule for intestinal delivery and evaluate, preliminarily, its cytotoxic ability against leukemic cells. MATERIAL AND METHODS: Five nanocapsule formulations were designed by the solvent displacement-evaporation method. Poly-ε-caprolactone, Eudragit® E100, and Kollicoat® Mae 100 P were used as film-former materials. Particle size, polydispersity index (PdI), zeta potential, and the pH of all formulations were measured. The cytotoxic potential of the nanocapsules was evaluated in vitro using different leukemic lineages RESULTS: Nanocapsules coated with Kollicoat® Mae 100 P presented the smallest particle size (130 nm), the lowest zeta-potential (-38 mV), and the narrowest size distribution (PdI = 0.100). The entrapment efficiency was 65.47%, while the loading capacity was 2.40%. Nanocapsules release 100% of α-amyrin in 40 min (pH 7.4), by using a possible mechanism of swelling-diffusion. The formulation showed excellent on-shelf physicochemical stability during one year. Additionally, nanocapsules produced a selective cytotoxic effect on a human leukemia lineage Kasumi-1, an acute myeloid leukemia cell line, and produced cell death by apoptosis CONCLUSION: α-amyrin-loaded nanocapsules appear to be a promising nanoformulation that could be used against leukemia.

Antiviral Activity of the PropylamylatinTM Formula against the Novel Coronavirus SARS-CoV-2 In Vitro Using Direct Injection and Gas Assays in Virus Suspensions.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of novel coronavirus disease 2019 (COVID-19), has become a severe threat to global public health. There are currently no antiviral therapies approved for the treatment or prevention of mild to moderate COVID-19 as remdesivir is only approved for severe COVID-19 cases. Here, we evaluated the antiviral potential of a Propylamylatin formula, which is a mixture of propionic acid and isoamyl hexanoates. The Propylamylatin formula was investigated in gaseous and liquid phases against 1 mL viral suspensions containing 105 PFU of SARS-CoV-2. Viral suspensions were sampled at various times post-exposure and infectious virus was quantified by plaque assay on Vero E6 cells. Propylamylatin formula vapors were effective at inactivating infectious SARS-CoV-2 to undetectable levels at room temperature and body temperature, but the decline in virus was substantially faster at the higher temperature (15 min versus 24 h). The direct injection of liquid Propylamylatin formula into viral suspensions also completely inactivated SARS-CoV-2 and the rapidity of inactivation occurred in an exposure dependent manner. The overall volume that resulted in 90% viral inactivation over the course of the direct injection experiment (EC90) was 4.28 µls. Further investigation revealed that the majority of the antiviral effect was attributed to the propionic acid which yielded an overall EC90 value of 11.50 µls whereas the isoamyl hexanoates provided at most a 10-fold reduction in infectious virus. The combination of propionic acid and isoamyl hexanoates was much more potent than the individual components alone, suggesting synergy between these components. These findings illustrate the therapeutic promise of the Propylamylatin formula as a potential treatment strategy for COVID-19 and future studies are warranted.

Novel Glutamine Antagonist JHU395 Suppresses MYC-Driven Medulloblastoma Growth and Induces Apoptosis.

Medulloblastoma is the most common malignant pediatric brain tumor. Amplification of c-MYC is a hallmark of a subset of poor-prognosis medulloblastoma. MYC upregulates glutamine metabolism across many types of cancer. We modified the naturally occurring glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) by adding 2 promoeities to increase its lipophilicity and brain penetration creating the prodrug isopropyl 6-diazo-5-oxo-2-(((phenyl (pivaloyloxy) methoxy) - carbonyl) amino) hexanoate, termed JHU395. This prodrug was shown to have a 10-fold improved CSF-to-plasma ratio and brain-to-plasma ratio relative to DON. We hypothesized that JHU395 would have superior cell penetration compared with DON and would effectively and more potently kill MYC-expressing medulloblastoma. JHU395 treatment caused decreased growth and increased apoptosis in multiple human high-MYC medulloblastoma cell lines at lower concentrations than DON. Parenteral administration of JHU395 in Nu/Nu mice led to the accumulation of micromolar concentrations of DON in brain. Treatment of mice bearing orthotopic xenografts of human MYC-amplified medulloblastoma with JHU395 increased median survival from 26 to 45 days compared with vehicle control mice (p < 0.001 by log-rank test). These data provide preclinical justification for the ongoing development and testing of brain-targeted DON prodrugs for use in medulloblastoma.

Short-Chain Fatty Acids (Except Hexanoic Acid) Lower NF-kB Transactivation, Which Rescues Inflammation-Induced Decreased Apolipoprotein A-I Transcription in HepG2 Cells.

Concentrations of apolipoprotein A-I (ApoA-I) decrease during inflammation, which may lead to dysfunctional ApoA-I-poor high-density lipoprotein (HDL) particles, and as such, elevate cardiovascular risk. Therefore, rescuing ApoA-I concentrations, especially during inflammation, seems beneficial. Recently, short-chain fatty acids (SCFAs) have received more attention as a strategy in reversing atherosclerosis. We here evaluated the effects of SCFAs on inflammatory pathways in relation to ApoA-I transcription. SCFAs dose-response studies were performed in the presence and absence of inflammatory cytokines. ApoA-I and interleukin 8 (IL-8) mRNA expression were analyzed using qPCR and ELISA, respectively. To study underlying mechanisms, nuclear factor kappa B (NF-κB) transactivation and changes in mRNA expressions of the genes targets of bromodomain and extra-terminal (BET) inhibition, peroxisome proliferator-activated receptor-alpha (PPARα) transactivation and activator protein 1 (AP-1) pathway were analyzed. SCFAs (except hexanoic acid) increased ApoA-I mRNA transcription in both normal and inflammatory conditions and lowered IL-8 mRNA expression. This anti-inflammatory effect of SCFAs was confirmed by inhibition of NF-κB transactivation. Moreover, butyric acid increased carnitine palmitoyltransferase 1 (CPT1), PPARα target gene, mRNA transcription in both conditions, and there was a negative correlation between CPT1 and NF-κB. Therefore, PPARα transactivation is probably involved in the anti-inflammatory effects of SCFAs, which rescues ApoA-I transcription. In conclusion, propionate, butyrate and valerate elicit anti-inflammatory effects which might rescue ApoA-I transcription in inflammatory conditions via PPARα transactivation mediated NF-κB inhibition.

Dual Stimuli-Responsive Supramolecular Self-Assemblies Based on the Host-Guest Interaction between ß-Cyclodextrin and Azobenzene for Cellular Drug Release.

Health has always been a hot topic of concern, whereas cancer is one of the largest security risks to human health. Although the existing drug delivery systems (DDSs) have been extensively reported and commercially applied, there are still some issues that have yet to be well-resolved, including the toxicity, side-effects, and targeted therapy efficiency of drugs. Consequently, it is still necessary to develop a novel, highly efficient, controlled and targeted DDS for cancer therapy. For this, a supramolecular polymer, ß-CD-g-PDMAEMA@Azo-PCL, was designed and developed through the host-guest inclusion complexation interactions between a host polymer, ß-cyclodextrin-graft-poly(2-(dimethylamino)ethyl methacrylate) (ß-CD-g-PDMAEMA), and a guest polymer, azobenzene modified poly(ε-caprolactone) (Azo-PCL), and was characterized by various analysis techniques. The supramolecular assembly was examined in various pH environments and/or under UV-vis irradiation, showing the formation of supramolecular assemblies from regular spherical shapes to irregular aggregates with various hydrodynamic diameters. The 2D NOESY NMR studies showed the formation of inclusion complexation between Azo-PCL and ß-CD-g-PDMAEMA and between ß-CD and the side groups of PDMAEMA. The supramolecular assemblies could encapsulate doxorubicin to form spherical core-shell drug-carrying micelles with an entrapment efficiency of 66.1%. The effects of external environment stimuli on the in vitro drug release were investigated, showing light- and pH-modulated drug release properties. The cytotoxicity assessment indicated that the blank supramolecular micelles were nontoxic, whereas the drug-loaded micelles exhibited comparable or even superior anticancer activity to the anticancer activity of free DOX and inhibition of cancer cell proliferation. Therefore, the developed supramolecular assemblies can potentially be used as drug-controlled release carriers.

Fabrication and Application of a 3D-Printed Poly-ε-Caprolactone Cage Scaffold for Bone Tissue Engineering.

Poly-ε-caprolactone (PCL) is a promising synthetic material in bone tissue engineering (BTE). Particularly, the introduction of rapid prototyping (RP) represents the possibility of manufacturing PCL scaffolds with customized appearances and structures. Bio-Oss is a natural bone mineral matrix with significant osteogenic effects; however, it has limitations in being constructed and maintained into specific shapes and sites. In this study, we used RP and fabricated a hollow-structured cage-shaped PCL scaffold loaded with Bio-Oss to form a hybrid scaffold for BTE. Moreover, we adopted NaOH surface treatment to improve PCL hydrophilicity and enhance cell adhesion. The results showed that the NaOH-treated hybrid scaffold could enhance the osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMMSCs) both in vitro and in vivo. Altogether, we reveal a novel hybrid scaffold that not only possesses osteoinductive function to promote bone formation but can also be fabricated into specific forms. This scaffold design may have great application potential in bone tissue engineering.

Electrospun poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/silk fibroin film is a promising scaffold for bone tissue engineering.

Polyhydroxyalkanoates (PHAs) are biodegradable polyesters produced by microorganisms, under unbalanced growth conditions, as a carbon storage compound. PHAs are composed of various monomers such as 3-hydroxybutyrate (3HB) and 3-hydroxyhexanoate (3HHx). Silk fibroin (SF) derived from Bombyx mori cocoons, is a widely studied protein polymer commonly used for biomaterial applications. In this study, non-woven electrospun films comprising a copolymer of 3HB and 3HHx [P(3HB-co-3HHx)], SF and their blends were prepared by electrospinning technique. The growth and osteogenic differentiation of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) were studied using different types of fabricated electrospun films. The differentiation study revealed that electrospun P(3HB-co-3HHx)/SF film supports the differentiation of hUC-MSCs into the osteogenic lineage, confirmed by histological analysis using Alizarin Red staining, energy dispersive X-ray (EDX) and quantitative real-time PCR analysis (qPCR). Electrospun P(3HB-co-3HHx)/SF film up-regulated the expression of osteogenic marker genes, alkaline phosphatase (ALP) and osteocalcin (OCN), by 1.6-fold and 2.8-fold respectively, after 21 days of osteogenic induction. In conclusion, proliferation and osteogenic differentiation of hUC-MSCs were enhanced through the blending of P(3HB-co-3HHx) and SF. The results from this study suggest that electrospun P(3HB-co-3HHx)/SF film is a promising biomaterial for bone tissue engineering.

131I-labeled and DOX-loaded multifunctional nanoliposomes for radiotherapy and chemotherapy in brain gliomas.

The codelivery of different therapeutics is a promising option because of its synergetic effects of drugs. In this study, a new combination therapy that used the doxorubicin-loaded and 131I-labeled nanoliposomes (131I-DOX-NL) was proposed to delay tumor growth of gliomas, which are characterized by significant mortality and morbidity. 131I-DOX-NL was constructed based on bovine serum albumin (BSA)-tailor made hydrophobic maleimide-functionalized poly(ε-caprolactone) (PCL) (Fig. 1) and was evaluated by cellular viability in vitro and by U87 xenograft models in vivo. Compared with using 131I-NL or DOX-NL alone, our experimental results show that 131I-DOX-NL exhibits similar high cellular uptake but enhanced efficacy to cure gliomas because of its codelivery of 131I and DOX. In the U87 mouse tumor models, the combination therapy resulted in higher survival rates of mice and smaller tumor sizes than monotherapy did alone. In conclusion, multifunctional nanoliposome 131I-DOX-NL is a good candidate for the codelivery of 131I-mediated radiotherapy and DOX-mediated chemotherapy due to its ability to inhibit U87 cell proliferation and tumor growth. 131I-DOX-NL can be used as a promising effective therapy for malignant gliomas and deserves further investigation.

Poly-ε-caprolactone scaffold for the reinforcement of stapled small intestinal anastomoses: a randomized experimental study.

BACKGROUND: Anastomotic leakage is a severe complication in gastrointestinal surgery. Different methods have been evaluated for anastomotic reinforcement to prevent anastomotic leakage. The aim of this study was to investigate the effect of a poly-ε-caprolactone (PCL) scaffold incorporated in the staple-line, on the anastomotic strength and histological wound healing, of small intestinal anastomoses in piglets. METHOD: This randomized experimental trial included 17 piglets. In each piglet, three end-to-end anastomoses were performed in the small intestine with a circular stapler, i.e. one control and two interventional anastomoses. On postoperative day 5, the anastomoses were resected and subjected to tension stretch test and histological examination. RESULTS: No anastomotic leakage occurred. In the interventional anastomoses, the mean value for maximal tensile strength was 15.7 N, which was significantly higher than control anastomoses 12.7 N (p = 0.01). No statistically significant differences were found between the two groups in the histopathological parameters. CONCLUSION: To conclude, this study has shown that the incorporation of a PCL scaffold in the staple-line was feasible and significantly increased the maximal tensile strength of small intestine anastomoses in piglets on postoperative day 5. The difference in histological parameters was not significantly distinct.

Glutamine blockade induces divergent metabolic programs to overcome tumor immune evasion.

The metabolic characteristics of tumors present considerable hurdles to immune cell function and cancer immunotherapy. Using a glutamine antagonist, we metabolically dismantled the immunosuppressive microenvironment of tumors. We demonstrate that glutamine blockade in tumor-bearing mice suppresses oxidative and glycolytic metabolism of cancer cells, leading to decreased hypoxia, acidosis, and nutrient depletion. By contrast, effector T cells responded to glutamine antagonism by markedly up-regulating oxidative metabolism and adopting a long-lived, highly activated phenotype. These divergent changes in cellular metabolism and programming form the basis for potent antitumor responses. Glutamine antagonism therefore exposes a previously undefined difference in metabolic plasticity between cancer cells and effector T cells that can be exploited as a "metabolic checkpoint" for tumor immunotherapy.

The dietary combination of essential oils and organic acids reduces Salmonella enteritidis in challenged chicks.

This study was conducted to determine the effects of essential oils and organic acids (EOA) on Salmonella Enteritidis (S. Enteritidis) challenged chickens. One-day-old specific pathogen-free (SPF) chicks (250) were randomly assigned to 5 groups, with 50 birds in each group. The treatment groups were as follows: 1) basal diet, negative control group (NC); 2) basal diet + S. Enteritidis, positive control group (PC); 3) PC + 4,000 g/t of enrofloxacin (5%), antibiotic group (ENR); 4) PC + 800 g/t of EOA1, thymol-benzoic acid group (TBA); and 5) PC + 800 g/t of EOA2, cinnamylaldehyde-caproic acid group (CCA). At 7 D of age, each bird, except those in NC, was orally gavaged with 0.4 mL of a suspension of 4.4 × 109 cfu S. Enteritidis/mL. Results revealed that ENR reduced bacterial counts in the liver and spleen on days 3, 5, and 7 post-challenge more (P < 0.05) than any other treatments. However, bacterial counts in cecal contents among ENR, TBA, and CCA were similar at 5 and 7 D post-challenge but lower than those of PC. Additionally, the bacterial counts in liver, spleen, and cecum contents in TBA were lower (P < 0.05) than in PC at 3, 5, and 7 D post-challenge; the bacterial counts in spleen contents in TBA were lower (P < 0.05) than in CCA at 7 D post-challenge. Tumor necrosis factor-α contents in TBA and CCA were lower (P < 0.05) than those in PC. Also, the ratio of villus height to crypt depth in the ileum of CCA was higher (P < 0.05) than that of PC and ENR; however, there was no difference in the secretory IgA content of the jejunum among the groups. In conclusion, EOA had a bacteriostatic effect on S. Enteritidis, and the effect of the thymol-benzoic acid complex surpassed that of the cinnamaldehyde-caproic acid complex. Therefore, EOA may act as an effective antibiotic substitute for animals in the prevention and treatment of Salmonella.

Chondrocyte Co-cultures with the Stromal Vascular Fraction of Adipose Tissue in Polyhydroxybutyrate/Poly-(hydroxybutyrate-co-hydroxyhexanoate) Scaffolds: Evaluation of Cartilage Repair in Rabbit.

Chondral defects are challenging to repair because of the poor self-healing capacity of articular cartilage. The aim of this study was to compare and investigate the cartilage regeneration of stromal vascular fraction (SVF) cells and adipose-derived stem cells (ASCs) co-cultured with chondrocytes seeding on scaffolds composed of polyhydroxybutyrate (PHB)/poly-(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx). In this study, the cellular morphologies and proliferation capabilities on scaffolds were evaluated. Next, scaffolds with 1:1 co-culture of ASCs/SVF and chondrocytes were implanted into the full-thickness cartilage defects in rabbit knee for 10 weeks. Cells seeded on the scaffolds showed better adhesion, migration, and proliferation in vitro. Importantly, implantation with scaffolds with SVF and chondrocytes revealed more desirable in vivo healing outcomes. Our results illustrate a one-step surgical procedure for the regeneration of focal cartilage defects using a mixture of SVF from adipose tissue and uncultured chondrocytes.

Lithium Chloride-Releasing 3D Printed Scaffold for Enhanced Cartilage Regeneration.

BACKGROUND We synthetized a 3D printed poly-ε-caprolactone (PCL) scaffold with polydopamine (PDA) coating and lithium chloride (LiCl) deposition for cartilage tissue engineering and analyzed its effect on promoting rabbit bone marrow mesenchymal stem cells (rBMSC) chondrogenesis in vitro. MATERIAL AND METHODS PCL scaffolds were prepared by 3D printing with a well-designed CAD digital model, then modified by PDA coating to produce PCL-PDA scaffolds. Finally, LiCl was deposited on the PDA coating to produce PCL-PDA-Li scaffolds. The physicochemical properties, bioactivity, and biocompatibility of PCL-PDA-Li scaffolds were accessed by comparing them with PCL scaffolds and PCL-PDA scaffolds. RESULTS 3D PCL scaffolds exhibited excellent mechanical integrity as designed. PDA coating and LiCl deposition improved surface hydrophilicity without sacrificing mechanical strength. Li⁺ release was durable and ion concentration did not reach the cytotoxicity level. This in vitro study showed that, compared to PCL scaffolds, PCL-PDA and PCL-PDA-Li scaffolds significantly increased glycosaminoglycan (GAG) formation and chondrogenic marker gene expression, while PCL-PDA-Li scaffolds showed far higher rBMSC viability and chondrogenesis. CONCLUSIONS 3D printed PCL-PDA-Li scaffolds promoted chondrogenesis in vitro and may provide a good method for lithium administration and be a potential candidate for cartilage tissue engineering.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Biopolyester Based Nanoparticles as NVP-BEZ235 Delivery Vehicle for Tumor Targeting Therapy.

As a biopolyester with excellent properties, the potential biomedical applications of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) have gained extensive attention. In this research, PHBHHx was fabricated into nanoparticles (NPs) to encapsulate NVP-BEZ235 (BEZ), an efficient kinase inhibitor/antitumor agent, for tumor targeting therapy. The resulting BEZ-NPs displayed a regularly spherical form with an appropriate diameter at 76.0 ± 3.6 nm. The encapsulation efficiency of BEZ was 83.7 ± 3.6%, and the sustained release profiles showed that almost 97% of BEZ could be gradually unrestricted from PHBHHx NPs within 72 h. The nanotoxicity studies revealed a satisfactory biosafety of PHBHHx NPs. PHBHHx NPs presented significantly improved cellular uptake in human prostate cancer cell line PC3, thereby enhancing the antiproliferation ability and kinase inhibitory activity of BEZ in vitro. More importantly, the in vivo real-time imaging demonstrated the adequate tumor targeting and accumulation capability of PHBHHx NPs. The remarkably delayed tumor growth, increased tumor necrosis, and reduced tumor proliferation in PC3 tumor xenograft mice further confirmed the antitumor efficacies of BEZ-loaded PHBHHx NPs. The above results suggest that PHBHHx NPs might be a promising drug delivery vehicle, safe and effective, for tumor targeting therapy.