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Scaffold hopping refers to computer-aided screening for active compounds with different structures against the same receptor to enrich privileged scaffolds, which is a topic of high interest in organic and medicinal chemistry. However, most approaches cannot efficiently predict the potency level of candidates after scaffold hopping. Herein, we identified potent PDE5 inhibitors with a novel scaffold via a free energy perturbation (FEP)-guided scaffold-hopping strategy, and FEP shows great advantages to precisely predict the theoretical binding potencies Δ G FEP between ligands and their target, which were more consistent with the experimental binding potencies Δ G EXP (the mean absolute deviations | Δ G FEP − Δ G EXP | < 2 kcal/mol) than those Δ G MM-PBSA or Δ G MM-GBSA predicted by the MM-PBSA or MM-GBSA method. Lead L12 had an IC 50 of 8.7 nmol/L and exhibited a different binding pattern in its crystal structure with PDE5 from the famous starting drug tadalafil. Our work provides the first report via the FEP-guided scaffold hopping strategy for potent inhibitor discovery with a novel scaffold, implying that it will have a variety of future applications in rational molecular design and drug discovery. Our work provides the first report about the free energy perturbation (FEP)-guided scaffold hopping strategy (|Δ G FEP –Δ G EXP |< 2 kcal/mol) to discover potent inhibitors with a novel scaffold. [Display omitted] [ABSTRACT FROM AUTHOR]

Optimization efforts were devoted to discover novel PDE10A inhibitors in order to improve solubility and pharmacokinetics properties for a long-term therapy against pulmonary arterial hypertension (PAH) starting from the previously synthesized inhibitor A. As a result, a potent and highly selective PDE10A inhibitor, 14· 3HCl (half maximal inhibitory concentration, IC 50 = 2.8 nmol/L and > 3500-fold selectivity) exhibiting desirable solubility and metabolic stability with a remarkable bioavailability of 50% was identified with the aid of efficient methods of binding free energy predictions. Animal PAH studies showed that the improvement offered by 14· 3HCl [2.5 mg/kg, oral administration (p.o.)] was comparable to tadalafil (5.0 mg/kg, p.o.), verifying the feasibility of PDE10A inhibitors for the anti-PAH treatment. The crystal structure of the PDE10A− 14 complex illustrates their binding pattern, which provided a guideline for rational design of highly selective PDE10A inhibitors. A potent and highly selective PDE10A inhibitor, 14 ·3HCl (IC 50 = 2.8 nmol/L and > 3500-folds selectivity) with a remarkable bioavailability of 50% was obtained to verify the feasibility for the anti-PAH treatment. The crystal structure of PDE10A– 14 complex illustrated the binding pattern, providing a guideline for rational design of highly selective PDE10A inhibitors. Image 1 [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause acute respiratory distress syndrome, hypercoagulability, hypertension, and multiorgan dysfunction. Effective antivirals with safe clinical profile are urgently needed to improve the overall prognosis. In an analysis of a randomly collected cohort of 124 patients with COVID-19, we found that hypercoagulability as indicated by elevated concentrations of D-dimers was associated with disease severity. By virtual screening of a U.S. FDA approved drug library, we identified an anticoagulation agent dipyridamole (DIP) in silico , which suppressed SARS-CoV-2 replication in vitro. In a proof-of-concept trial involving 31 patients with COVID-19, DIP supplementation was associated with significantly decreased concentrations of D-dimers (P < 0.05), increased lymphocyte and platelet recovery in the circulation, and markedly improved clinical outcomes in comparison to the control patients. In particular, all 8 of the DIP-treated severely ill patients showed remarkable improvement: 7 patients (87.5%) achieved clinical cure and were discharged from the hospitals while the remaining 1 patient (12.5%) was in clinical remission. Dipyridamole bound to the SARS-CoV-2 protease Mpro after identified via the virtual screening and bioassay validation, and thus suppressed viral replication in vitro. As a result, dipyridamole supplementation was associated with significantly decreased concentrations of D-dimers, increased lymphocyte and platelet recovery in the circulation, and markedly improved clinical outcomes in comparison to the control patients. Image 1 [ABSTRACT FROM AUTHOR]

The ethanolic extract of Aloe barbadensis Miller leaf skin showed inhibitory activity against phosphodiesterase-4D (PDE4D), which is a therapeutic target of inflammatory disease. Subsequent bioassay-guided fractionation led to the isolation of two new anthrones, 6′- O -acetyl-aloin B ( 9 ) and 6′- O -acetyl-aloin A ( 11 ), one new chromone, aloeresin K ( 8 ), together with thirteen known compounds. Their chemical structures were elucidated by spectroscopic methods including UV, IR, 1D and 2D NMR, and HRMS. All of the isolates were screened for their inhibitory activity against PDE4D using tritium-labeled adenosine 3′,5′-cyclic monophosphate ( 3 H-cAMP) as substrate. Compounds 13 and 14 were identified as PDE4D inhibitors, with their IC 50 values of 9.25 and 4.42 μM, respectively. These achievements can provide evidences for the use of A. barbadensis leaf skin as functional feed additives for anti-inflammatory purpose. [ABSTRACT FROM AUTHOR]

Mucosal surfaces contain specialized dendritic cells (DCs) that are able to recognize foreign pathogens and mount protective immunity. We previously demonstrated that intranasal administration of targeted galactosylated liposomes can elicit mucosal and systemic antibody responses. In the present study, we assessed whether galactosylated liposomes could act as an effective DC-targeted mucosal vaccine that would be capable of inducing systemic anti-tumor immunity as well as antibody responses. We show that targeted galactosylated liposomes effectively facilitated antigen uptake by DCs beyond that mediated by unmodified liposomes both in vitro and in vivo. Targeted galactosylated liposomes induced higher levels of pro-inflammatory cytokines than unmodified liposomes in vitro. C57BL/6 mice thrice immunized intranasally with ovalbumin (OVA)-encapsulated galactosylated liposomes produced high levels of OVA-specific IgG antibodies in their serum. Spleen cells from mice receiving galactosylated liposomes were restimulated with OVA and showed significantly augmented levels of IFN-γ, IL-4, IL-5 and IL-6. In addition, intranasal administration of OVA-encapsulated beta-galactosylated liposomes resulted in complete protection against EG7 tumor challenge in C57BL/6 mice. Taken together, these results indicate that nasal administration of a galactosylated liposome vaccine mediates the development of an effective immunity against tumors and might be useful for further clinical anti-tumoral applications. [ABSTRACT FROM AUTHOR]

Abstract: Bioassay-guided fractionation of the ethanol extract of the Chinese folk medicine Crotalaria ferruginea led to the isolation of a new isoflavonoid, 4′-hydroxy-2′-methylalpinum-isoflavone (1), and eight known analogs (2–9). Their structures were elucidated by spectroscopic analysis. Compounds 1, 2, 5, and 8 showed inhibitory activities against phosphodiesterase-4 (PDE4), a therapeutic target of asthma, with IC50 values ranging from 2.57 to 8.94μM. The possible action mechanism and the structure–activity relationship (SAR) of the active isoflavonoids were explored by using molecular docking and molecular dynamics (MD) simulation methods. Our study herein may explain the anti-inflammatory function of this plant in Chinese folk medicine. [Copyright &y& Elsevier]

Abstract: The mucosal immune system produces secretory IgA (sIgA) as the first line of defense against invasion by foreign pathogens. Our aim was to develop a galactose-modified liposome as a targeted carrier which can be specifically recognized by macrophage, one of the most important antigen presenting cells. First, galactose was covalently conjugated with 1,2-didodecanoyl-sn-glycero-3-phosphoethanolamine (DLPE) to give a targeted ligand, a galactosyl lipid. The galactosyl lipid was then incorporated into a liposomal bilayer to form a galactosylated liposome carrier. Further, the ovalbumin (OVA) was encapsulated into the galactosylated liposome carriers and mice were intranasally immunized. Confocal laser scanning microscopy and flow cytometry analysis showed that the targeted galactosylated liposome carrier had a higher uptake rate than unmodified liposomes. The targeted galactosylated liposome induced higher levels of tumor necrosis factor-α and interleukin-6 production than unmodified liposomes (P <0.05). Furthermore, 6-week-old BALB/c female mice immunized with the OVA-encapsulated targeted galactosylated liposome had significantly higher OVA-specific s-IgA levels in the nasal and lung wash fluid (P <0.05). In addition, the targeted galactosylated liposome simultaneously augmented the serum IgG antibody response. In summary, the OVA-encapsulated targeted galactosylated liposome induced significantly higher mucosal IgA and systemic IgG antibody titers and is a potential antigen delivery carrier for further clinical applications. [Copyright &y& Elsevier]

Abstract: In this work we have developed a strategy for cultivating dermal papilla (DP) cells to form multiple arrayed spheroidal microtissues for transplantation on a micropatterned polydimethylsiloxane (PDMS)-based tissue culture polystyrene (TCPS) plate system. We also describe the behavior of dermal papilla cells on this platform and the spontaneous formation of spheroidal microtissues by DP cells. We used a hydrophobic PDMS arrayed chip as a master to separate the seeded cells in the TCPS culture plate. By controlling the cell seeding densities, a microwell with arrayed DP spheroidal microtissues was easily formed. Formation of DP microtissues was associated with overlapping multilayered cells on the microwells and low cell–substrate adhesivity on the PDMS film. The microwell environment enhanced the aggregation of DP cells into spheroidal microtissues on the TCPS culture plate. The spheroidal microtissues preserved their hair induction potential in vitro and in vivo. A large quantity of DP spheroidal microtissues could be obtained rapidly and simply using this platform. We could harvest hundreds of DP microtissues (352 microtissues) with a cell seeding density of 1×106 cells well−1 after 3days cultivation in one well of a 24-well plate. This is the first demonstration of the formation of DP spheres in large quantitites. [ABSTRACT FROM AUTHOR]

Abstract: The major role of disaster recovery management is to rapidly restore the chaotic condition to normal, which includes mitigation, preparedness, response, and recovery. To reduce secondary damage and loss, the recovery process must be facilitated. Information technologies (including network, web-based, computer, and related software tools) speed up the work process to rapidly deliver disaster information to the related department. In this paper, we share an experience that used a framework of emergency response, including a simple pre-operating process and a web-based information system, to effectively manage and control damaged medical equipment after a fire accident in a hospital operating room. This web-based information system was built in only 2weeks and was used to manage a large amount of medical equipment affected by the fire. Since then, it effectively prevented the interruption of clinical work at 22 clinical units by supporting the reconstruction activities. [Copyright &y& Elsevier]

Abstract: The tissue injury and the organization of collagen during cryosurgery are poorly characterized because of the lack of appropriate methodologies. In this study, we use multimodal multiphoton microscopy to assess the change of extracellular matrix after cryotreatment of skin. The cellular matrix transformations and the intercellular interactions during the wound healing process after cryolesion for mice were measured in vivo and in real-time through the dorsal skinfold chamber (DSC). Intrinsic second-harmonic generation (SHG) signals from fibrillar collagen and two-photon excited (TPE) autofluorescence from cell were collected to investigate the cryosurgical response in vivo. The TPE and SHG signals are significantly different between normal and cryotreated mice, and correlates with the wound healing process. The results suggest that this approach may be applied in real-time to noninvasively monitor the cryosurgery process and could potentially be applied to clinical evaluation. [Copyright &y& Elsevier]

In the present study, we attempted to develop a lecithin-stabilized micellar drug delivery system (L sb MDDs) for loading docetaxel (DTX) to enhance its therapeutic efficacy and minimize systemic toxicity. A novel DTX-loaded L sb MDDs was optimally prepared by a thin-film hydration method and then hydrated with a lecithin nanosuspension while being subjected to ultrasonication. Physical characteristics of the optimized DTX-loaded L sb MDDs formulations were examined and found to have a mean size of <200 nm, an encapsulation efficiency of >90%, and drug loading of >6% with stability at room temperature and at 4 °C being longer than 2 and 7 days, respectively. The in vitro release of DTX from the DTX-loaded L sb MDDs was slower than that from the generic product of DTX (Tynen®). A cell viability assay demonstrated that the L sb MDDs showed better cytotoxicity than Tynen® against CT26 cancer cells. The in vivo antitumor efficacy of the DTX-loaded L sb MDDs was observed to be better than that of Tynen® in a CT26 tumor-bearing mice model. A high-dose regimen of the DTX-loaded L sb MDDs formulation showed greater inhibition of DU145 tumor growth than did Tynen®, but with less to similar systemic toxicity. An in vivo study also showed that a greater amount of drug was able to accumulate in the tumor site with the DTX-loaded L sb MDDs, and its maximal tolerable doses for single and repeated injections were 2–2.5-fold higher than those of Tynen®. In conclusion, the L sb MDDs could be a promising high drug-loaded nanocarrier for delivering hydrophobic chemotherapeutic agents that can enhance the efficacy of chemotherapy and reduce systemic toxicity. [ABSTRACT FROM AUTHOR]

Cavitation plays a substantial role in the clinical effects of extracorporeal shock wave therapy (ESWT). It is also generally accepted as a major mechanism in sonophoresis. To identify the enhancing effect of extracorporeal shock wave-mediated transdermal drug delivery, 24 Wistar rats were randomly assigned to four groups: (i) topical application of a eutectic mixture of local anesthetics (EMLA); (ii) 1-MHz ultrasound; (iii) ESWT pre-treatment combined with EMLA application; (iv) ESWT concurrent with EMLA application on rat tails. The degree of anesthesia was assessed using the amplitude and latency of sensory nerve action potentials within 5 min after a 60-min EMLA application. The results indicated that ESWT pre-treatment and concurrent ESWT accelerated the anesthetic effects of the EMLA cream on the tail nerve (p < 0.05). This finding might indicate that shock wave-mediated transdermal drug delivery is possible during the ESWT period. [ABSTRACT FROM AUTHOR]

Inflammatory Bowel Diseases (IBDs) are chronic disorders with iterative intestinal mucosal inflammation which remain unmet medical needs. PDE4 inhibitors were reported to be novel anti-IBD agents, but their clinical use was hampered by side effects such as emesis and nausea. Herein, structure-based discovery of natural mangostanin (1) targeting the M-pocket resulted in the novel and potent PDE4 inhibitor 22d (IC 50 = 3.5 nM) and favorable physico-chemical properties. X-Ray study revealed that 22d interacted tightly with the M-pocket and maintained the key interactions between PDE4 and roflumilast. Worthy to note that compounds 22d and our previously reported 4e and 18a , originating from mangostanin, all caused no emesis on beagle dogs at the oral dose of 10 mg/kg, confirming the safety superiority of scaffold in mangostanin derivatives over that in positive roflumilast. Finally, administration of 22d (5.0 mg/kg, twice-daily) exhibited comparable anti-IBD effects to the positive control dipyridamole (25.0 mg/kg, twice-daily) in the dextran sulfate sodium (DSS)-induced IBD mice model, indicating its potential as a novel anti-IBD agent. [Display omitted] • Lead 22d had maintained the safety superiority of the mangostanin scaffold (emetic dose >10 mg/kg) and simulated the key interactions between PDE4 and highly potent roflumilast (inhibitory IC 50 of 3.5 nM). • Lead 22d was a potential novel agent for treatment of Inflammatory Bowel Diseases. • Their co-crystal structures revealed that interacting with the M pocket was an effective strategy to improve the potencies of PDE4 inhibitors. [ABSTRACT FROM AUTHOR]

[Display omitted] Phosphodiesterase-4 (PDE4) is an important drug target for inflammatory diseases. Previously, we identified a series of novel PDE4 inhibitors derived from the natural Toddacoumalone, among which the hit compound 2 with a naphthyridine scaffold showed moderate potency with the IC 50 value of 400 nM. Based on the co-crystal structure of PDE4D- 2 , further structural optimizations and structure–activity relationship studies led to a highly potent PDE4 inhibitor 23a with the IC 50 value of 0.25 nM and excellent selectivity profiles over other PDEs (>4000-fold). The co-crystal structure of PDE4D- 23a elucidated that 23a has strong interactions with the M and Q pocket of PDE4D. Importantly, compound 23a significantly inhibits the release of inflammatory cytokines TNF- α and IL-6 in lipopolysaccharide-stimulated RAW264.7 cells. Thus, compound 23a with a naphthyridine scaffold is a promising PDE4 inhibitor for the treatment of inflammatory diseases. [ABSTRACT FROM AUTHOR]

Abstract: Spinal cord injury (SCI) can trigger inhibitory signal cascades that promote the expression of chondroitin sulfate proteoglycans (CSPGs), which are the main structures in scar tissue. The digestion of CSPGs by chondroitinase ABC (ChABC) can promote axonal re-growth after SCI. However, ChABC cannot effectively digest CSPGs because it is unstable; therefore, stable ChABC must be released in a controlled manner in the repair of SCIs. Two methods of maintaining ChABC stability and bioactivity were examined. They were the immobilization of ChABC on nerve conduits (NCs) and the encapsulation of ChABC in poly(d,l-lactic acid) (PDLLA) microspheres. Nerve conduits with variously sized pores were fabricated from chitosan and gelatin. The pore diameters of chitosan NCs were 100–160μm, and those of chitosan/gelatin NCs were 20–40μm. The ChABC in NCs was immobilized by ionic or covalent bonding. The experimental results reveal that immobilizing ChABC in NCs markedly improved its stability. The activity of ChABC that was immobilized in chitosan NCs by ionic bonding was 0.07U/mg; 48% of this activity was retained at 48h after immobilization. PDLLA microspheres, fabricated by the double emulsion method, were applied as carriers in the controlled release of ChABC. Stabilizers, including nanogold (10nm), polylysine (Mw: 500–2000) and polylysine (Mw: 20,000–30,000), were added to microspheres to maintain the activity of ChABC. Polylysine (Mw: 500–2000) stabilized ChABC most effectively. The ChABC activity was 0.0162U/ml after seven days of release. Experimental results indicate that ChABC activity can be preserved during release by immobilizing ChABC in chitosan NCs and encapsulating ChABC in PDLLA microspheres using an appropriate stabilizer. [Copyright &y& Elsevier]

Abstract: Poly(ε-caprolactone) (PCL) scaffolds were modified by grafting nerve growth factor (NGF) and Tirofiban (TF), a clinical anti-thrombosis drug, as a new biomaterial for producing nerve conduits to promote the regeneration of sciatic nerves. The successful grafting of NGF and TF onto PCL scaffolds was confirmed by FTIR and ESCA spectra. In-vitro growths of the PC12 cells in PCL-NGF and PCL-NGF/TF scaffolds, determined by MTS, were significantly higher (P < 0.05, n = 4) than those in the PCL scaffolds following three days of cultivation. Interestingly, this study evaluation of the PCL, PCL-NGF, and PCL-NGF/TF nerve conduits in a 12 mm long gap of the rat sciatic nerve defect model that the gastrocnemius muscle mass of the tested rats in the PCL-NGF/TF groups significantly exceeded those in the PCL-NGF and PCL group. In the rats that had been implanted with PCL-NGF/TF conduits, the generated nerves passed through those conduits, expressing beta-III tubulin (TB), growth association protein-43 (GAP-43) and myelin basic protein (MBP) along their longitudinal axis, and the proximal and distal nerve ends of the rats were successfully connected. Those that had been implanted with PCL and PCL-NGF conduits did not exhibit these effects, as revealed by an immunochemical study of the expressions of the proteins in the conduits. Moreover, counting within the dorsal horn of the spinal cord (C5) demonstrated that the numbers of CTB-HRP-labeled neurons in the rats that had been implanted with PCL-NGF/TF conduits were significantly higher than those in the other groups. In this study, in-vivo examinations of the use of newly designed PCL-NGF/TF conduits to promote the generation of nerves in a defective rat model significantly increased the gastrocnemius muscle mass, and led to the successful regeneration of nerves that bridged a 12 mm long defected gap of nerves in rats. However, more rats must be tested to confirm the efficacy the newly designed nerve conduits. [Copyright &y& Elsevier]

Abstract: Using excitation polarization-resolved second harmonic generation (SHG) microscopy, we measured SHG intensity as a function of the excitation polarization angle for type I and type II collagens. We determined the second order susceptibility (χ(2)) tensor ratios of type I and II collagens at each pixel, and displayed the results as images. We found that the χ(2) tensor ratios can be used to distinguish the two types of collagen. In particular, we obtained χ zzz/χ zxx = 1.40 ± 0.04 and χ xzx/χ zxx = 0.53 ± 0.10 for type I collagen from rat tail tendon, and χ zzz/χ zxx = 1.14 ± 0.09 and χ xzx/χ zxx = 0.29 ± 0.11 for type II collagen from rat trachea cartilage. We also applied this methodology on the label-free imaging of engineered cartilage tissue which produces type I and II collagen simultaneously. By displaying the χ(2) tensor ratios in the image format, the variation in the χ(2) tensor ratios can be used as a contrast mechanism for distinguishing type I and II collagens. [Copyright &y& Elsevier]

Abstract: Since MSCs contain an abundant of CD44 surface markers, it is of interesting to investigate whether CD44 on rat MSC (rMSCs) influenced cell growth, fibronectin expression and cardiomyogenic differentiation on new SF/HA cardiac patches. For this investigation, we examined the influences of rMSCs with or without a CD44-blockage treatment on the aforementioned issues after they were cultivated, and further induced by 5-aza on SF and SF/HA patches. The results showed that the relative growth rates of rMSCs cultured on cultural wells, SF/HA patches without or with a CD44-blockage treatment were 100%, 208.9±7.1 (%) or 48.4±6.0 (%) (n =3, for all), respectively, after five days of cultivations. Moreover, rMSCs cultivated on SF/HA patches highly promoted fibronectin expressions (e.g., 1.8×105/cell, in fluorescent intensity) while cells with a CD44-blockage treatment markedly diminished the expressions (e.g., 1.1×104/cell, in fluorescent intensity) on same patches. For investigating possible influences of CD44 surface markers of rMSCs on their cardiomyogenic differentiation, the expressions of specific cardiac genes of cells were examined by using real-time PCR analysis. The results indicated that 5-aza inducing rMSCs significantly promoted the expressions of Gata4, Nkx2.5, Tnnt2 and Actc1 genes (all, P <0.01 or better, n =3) on SF/HA patches compared with those expressions on SF patches and for cells with a CD44-blockage treatment on SF/HA patches. Furthermore, the intensity of the expressions of cardiotin and connexin 43 of 5-aza inducing rMSCs were markedly higher than those of cells with a CD44-blockage treatment after they were cultured on SF/HA patches. Through this study, we reported that CD44 surface markers of rMSCs highly influenced the proliferations, fibronectin expressions and cardiomyogenic differentiation of rMSCs cultivated on cardiac SF/HA patches. [Copyright &y& Elsevier]

Abstract: The aim of this study was to characterize a nasally delivered bioadhesive liposome using an inactivated H5N3 virus as a model antigen. Bioadhesive liposomes were developed using tremella (T) or xanthan gum (XG) as the bioadhesive polysaccharide. Using chickens as the target animal, we evaluated whether delivery of a bioadhesive liposomal influenza vaccine via a mucosal site of infection could improve vaccine effectiveness. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cytotoxicity assays demonstrated that T, XG and liposomes were non toxic to chicken spleen macrophages. Enzyme-linked immunosorbent assay (ELISA) was used to determine the adjuvant effect of the bioadhesive liposomal-vaccines. Chickens immunized with a low dose (200μL) of bioadhesive liposomal influenza vaccine had significantly higher mucosal and serum antibody levels (P <0.05). In addition, liposomes mixed with a low-viscosity bioadhesive gel used for nasal delivery resulted in superior antibody responses compared with liposomes mixed with a high-viscosity gel (P <0.05). This suggest that a low-viscosity gel mixed with liposomes is more suitable for nasal delivery, and that chickens elicit higher mucosal secretory immunoglobulin A (s-IgA) and serum IgG after two vaccinations. [Copyright &y& Elsevier]

Abstract: Polysaccharides and proteins profoundly impact the development and growth of tissues in the natural extra-cellular matrix (ECM). To mimic a natural ECM, polysaccharides were incorporated to/or co-sprayed with silk fibroin (SF) to produce SF/chitosan (CS) or SF/CS–hyaluronic acid (SF/CS–HA) microparticles that were further processed by mechanical pressing and genipin cross-linking to produce hybrid cardiac patches. The ATR–FTIR spectra confirm the co-existence of CS or CS–HA and SF in microparticles and patches. For evaluating the cellular responses of rMSCs to the SF/CS and SF/CS–HA cardiac patches, the growth of rMSCs and cardiomyogenic differentiation of 5-aza inducing rMSCs cultured on patches was examined. First, the isolated rMSCs were identified with various positive and negative surface markers such as CD 44 and CD 31 by a flow cytometric technique, respectively. For examining the growth of rMSCs on the patches, MTT viability assay was performed, and the results demonstrated that the growth of rMSCs on SF and SF-hybrid patches significantly exceeded (P <0.001) that on culture wells after seven days of cultivation. Additionally, the relative growth rates of rMSCs on SF/CS and SF/CS–HA hybrid patches were significantly better (P <0.01) than that on SF patches that were also observed by using vimentin stain to the cells. For instance, the relative cell growth rates (%) in cell culture wells, SF, SF/CS and SF/CS–HA patches were 100%, 282.9±6.5%, 337.0±8.0% and 332.6±6.6% (n =6, for all), respectively. For investigating the effects of the hybrid patches on cardiomyogenic differentiation of 5-aza inducing rMSCs, the expressions of specific cardiac genes of cells such as Gata4 and Nkx2.5 were examined by real-time quantitative polymerase chain reaction (real-time PCR) analysis. The results of cardiomyogenic differentiation of induced rMSCs on SF/CS and SF/CS–HA hybrid patches significantly improved the expressions of cardiac genes of Gata4, Nkx2.5, Tnnt2 and Actc1 genes (all, P <0.01 or better, n =3) than those on SF patches and culture wells. Interestingly, the results of cardiac gene expressions of the cells on the SF/CS–HA hybrid patches were the most pronounced in promoting cardiomyogenic differentiations in this investigation. Furthermore, immunofluorescence staining of cardiac proteins such as cardiotin and connexin 43 for induced rMSCs cultured on SF/CS and SF/CS–HA hybrid patches were much pronounced compared with SF patches, indicating the improvements of cardiomyogenic differentiation on the hybrid patches. The results of this study demonstrate that the SF/CS and SF/CS–HA hybrid patches may be promising biomaterials for regenerating infarcted cardiac tissues. [Copyright &y& Elsevier]