Intramyocardial delivery of human cardiac stem cell spheroids with enhanced cell engraftment ability and cardiomyogenic potential for myocardial infarct repair.

Strategies for stem cell-based cardiac regeneration and repair are key issues for the ischemic heart disease (IHD) patients with chronic complications related to ischemic necrosis. Cardiac stem cells (CSCs) have demonstrated high therapeutic efficacy for IHD treatment owing to their specific cardiac-lineage commitment. The therapeutic potential of CSCs could be further enhanced by designing a cellular spheroid formulation. The spheroid culture condition of CSCs was optimized to ensure regulated size and minimal core necrosis in the spheroids. The CSC spheroids revealed mRNA profiles of the factors related to cardiac regeneration, angiogenesis, anti-inflammatory, and cardiomyocyte differentiation with a higher expression level than the CSCs. Intramyocardially delivered CSC spheroids in the rat IHD model resulted in a significant increase in retention rate by 1.82-fold (day 3) and 1.98-fold (day 14) compared to CSCs. Endothelial cell differentiation and neovascularization of the engrafted CSC spheroids were noted in the infarcted myocardium. CSC spheroids significantly promoted cardiac regeneration: i.e., decreased infarction and fibrotic area (11.22% and 4.18%) and increased left ventricle thickness (0.62 mm) compared to the untreated group. Cardiac performance was also improved by 2.04-fold and 1.44-fold increase in the ejection fraction and fractional shortening, respectively. Intramyocardial administration of CSC spheroids might serve as an advanced therapeutic modality with enhanced cell engraftment and regenerative abilities for cardiac repair after myocardial infarction.

Intra-articular delivery of synovium-resident mesenchymal stem cells via BMP-7-loaded fibrous PLGA scaffolds for cartilage repair.

Delivery of synovium-resident mesenchymal stem cells (synMSCs) to cartilage defect site might provide a novel therapeutic modality for treatment of articular cartilage diseases. However, low isolation efficiency of synMSCs limits their therapeutic application. Niche-preserving non-enzymatic isolation of synMSCs was firstly attempted by employing micro-organ culture system based on recapitulating tissue-specific homeostasis ex vivo. The isolated synMSCs retained superior long-term growth competency, proliferation and chondrogenic potential to bone marrow-derived MSCs (BMSCs). It was noted that synMSCs demonstrated 9-fold increase in cartilaginous micro-tissue formation and 13-fold increase in sulfated proteoglycans deposition compared to BMSCs. For delivery of synMSCs, fibrous PLGA scaffolds were specifically designed for full-thickness osteochondral defects in rabbits. The scaffolds provided effective micro-environment for growth and host-integration of synMSCs. Combined delivery of synMSCs with bone morphogenetic proteins-7 (BMP-7) was designed to achieve synergistic therapeutic efficacy. BMP-7-loaded PLGA nanoparticles electrosprayed onto the scaffolds released BMP-7 over 2 weeks to conform with its aimed role in stimulating early stage endochondral ossification. Scaffold-supported combined administration of synMSCs with BMP-7 resulted in high proteoglycan and collagen type II induction and thick hyaline cartilage formation. Intra-articular co-delivery of synMSCs with BMP-7 via fibrous PLGA scaffolds may be a promising therapeutic modality for articular cartilage repair.

Therapeutic Effect of Dexamethasone for Noise-induced Hearing Loss: Systemic Versus Intratympanic Injection in Mice.

OBJECTIVE: Dexamethasone is commonly used clinically to treat noise-induced hearing loss (NIHL) because the drug exerts multiple anti-inflammatory effects. In the present study, we investigated the post-noise therapeutic effects of dexamethasone given systemically or via intratympanic injection in the mouse. ANIMALS: Twenty-four C57BL/6J mice were used. Eighteen experimental mice were exposed to 110 dB sound pressure level white noise and then divided into three groups: the noise, intraperitoneal dexamethasone injection (IP), and intratympanic dexamethasone injection (IT) groups. METHODS: Dexamethasone (3 mg/kg/d) was injected intraperitoneally for five successive days in the IP group. Intratympanic injections were given on post-noise days 1 and 4 in the IT group. We compared hearing levels, the architecture of the organ of Corti (OC), and the microscopic appearance of the medial olivocochlear efferent terminals (MOC ETs) among the groups. RESULTS: Both the IP and IT groups exhibited hearing recovery as revealed by auditory brainstem responses (ABRs), but recovery was not apparent in distortion product otoacoustic emissions (DPOAEs). OC degeneration as revealed by light microscopy was most extensive in the noise group and least extensive in the IP group. Scanning electron microscopy showed that the OC ultrastructure was better preserved in the IP than the IT group. Confocal microscopy showed that the ETs were shrunken in all noise-exposed groups as compared to the control group, but more shrunken in the dexamethasone-treated groups. Transmission electron microscopy showed that the MOC ET-outer hair cell (OHC) synapses were damaged in all noise-exposed groups, but the extent of degeneration was less in the IT than in the noise group. CONCLUSION: Dexamethasone exerts reliable therapeutic effects when used to treat NIHL. It seems that the protective effects may differ by the routes of administration as the OCs were better preserved in the IP group and the ET-OHC synapses were more intact in the IT group.

Levocetrizine has anti-inflammatory effects against Toll-like receptor (TLR)3 through the inhibition of Toll-IL-1 receptor (TIR)-domain-containing adapter inducing IFN-beta (TRIF) and receptor-interacting protein (RIP).

OBJECTIVE: To investigate the anti-inflammatory effect of levocetrizine (LCEZ) on the intracellular adhesion molecule-1 (ICAM-1) in human nasal epithelial cells stimulated by TLR3 and further analyze the anti-inflammatory mechanism of LCEZ in the MyD88-independent pathway before NF-κB is activated. METHODS: A primary culture of human nasal epithelial cells (HNECs) was generated from nasal polyps. After stimulation of epithelial cells with LTA, double-stranded RNA (dsRNA), and LPS, reverse transcription-polymerase chain reaction (RT-PCR) was performed at 1, 6, and 24 h to clarify the optimal stimulation of ICAM-1 in HNECs. To investigate the anti-inflammatory effects of LCEZ, HNECs were pretreated with three different concentrations of LCEZ (500, 50, and 5 nM) for 2 h. HNECs were washed and then stimulated with dsRNA. At 1, 6, and 24 h after stimulation, the level of ICAM-1 was measured by RT-PCR and ELISA. Western blots for TRIF and RIP were performed. RESULTS: The level of ICAM-1 was significantly elevated by dsRNA. Pretreatment with LCEZ decreased the secretion of ICAM-1, which was observed in RT-PCR and Western blots but not in ELISA analyses. The expression of TRIF and RIP, measured by Western blot, was decreased by pretreatment with LCEZ. CONCLUSION: The activation of HNECs by TLRs (especially TLR3) could trigger an inflammatory process, which might be inhibited by LCEZ through the suppression of TRIF and RIP proteins.