Icariin-loaded hydrogel with concurrent chondrogenesis and anti-inflammatory properties for promoting cartilage regeneration in a large animal model

Temporal modulation of inflammation and chondrogenesis through dendritic nanoparticle-mediated therapy with diclofenac surface modification and strontium ion encapsulation

Cartilage tissue engineering holds great promise for efficient cartilage regeneration. However, early inflammatory reactions to seed cells and/or scaffolds impede this process. Consequently, managing inflammation is of paramount importance. Moreover, due to the body's restricted chondrogenic capacity, inducing cartilage regeneration becomes imperative. Thus, a controlled platform is essential to establish an anti-inflammatory microenvironment before initiating the cartilage regeneration process. In this study, we utilized fifth-generation polyamidoamine dendrimers (G5) as a vehicle for drugs to create composite nanoparticles known as G5-Dic/Sr. These nanoparticles were generated by surface modification with diclofenac (Dic), known for its potent anti-inflammatory effects, and encapsulating strontium (Sr), which effectively induces chondrogenesis, within the core. Our findings indicated that the G5-Dic/Sr nanoparticle exhibited selective Dic release during the initial 9 days and gradual Sr release from days 3 to 15. Subsequently, these nanoparticles were incorporated into a gelatin methacryloyl (GelMA) hydrogel, resulting in GelMA@G5-Dic/Sr. In vitro assessments demonstrated GelMA@G5-Dic/Sr's biocompatibility with bone marrow stem cells (BMSCs). The enclosed nanoparticles effectively mitigated inflammation in lipopolysaccharide-induced RAW264.7 macrophages and significantly augmented chondrogenesis in BMSCs cocultures. Implanting BMSCs-loaded GelMA@G5-Dic/Sr hydrogels in immunocompetent rabbits for 2 and 6 weeks revealed diminished inflammation and enhanced cartilage formation compared to GelMA, GelMA@G5, GelMA@G5-Dic, and GelMA@G5/Sr hydrogels. Collectively, this study introduces an innovative strategy to advance cartilage regeneration by temporally modulating inflammation and chondrogenesis in immunocompetent animals. Through the development of a platform addressing the temporal modulation of inflammation and the limited chondrogenic capacity, we offer valuable insights to the field of cartilage tissue engineering.

Synergistic Effects of Icariin and Extracellular Vesicles Derived from Rabbit Synovial Membrane-Derived Mesenchymal Stem Cells on Osteochondral Repair via the Wnt/β-Catenin Pathway

Objectives

Osteochondral defects (OCDs) are localized areas of damaged cartilage and underlying subchondral bone that can produce pain and seriously impair joint function. Literature reports indicated that icariin (ICA) has the effect of promoting cartilage repair. However, its mechanism remains unclear. Here, we explored the effects of icariin and extracellular vesicles (EVs) from rabbit synovial-derived mesenchymal stem cells (rSMSCs) on repairing of OCDs.

Materials and Methods

Rabbit primary genicular chondrocytes (rPGCs), knee skeletal muscle cells (rSMCKs), and rSMSCs, and extracellular vesicles derived from the latter two cells (rSMCK-EVs and rSMSC-EVs) were isolated and identified. The rPGCs were stimulated with ICA, rSMSC-EVs either separately or in combination. The rSMCK-EVs were used as a control. After stimulation, chondrogenic-related markers were analyzed by quantitative RT-PCR and western blotting. Cell proliferation was determined by the CCK-8 assay. The preventative effects of ICA and SMSC-EVs in vivo were determined by H&E and toluidine blue staining. Immunohistochemical analyses were performed to evaluate the levels of COL2A1 and β-catenin in vivo. Results. In vitro, the proliferation of rPGCs was markedly increased by ICA treatment in a dose-dependent manner. When compared with ICA or rSMSC-EVs treatment alone, combined treatment with ICA and SMSC-EVs produced stronger stimulative effects on cell proliferation. Moreover, combined treatment with ICA and rSMSC-EVs promoted the expression of chondrogenic-related gene, including COL2A1, SOX-9, and RUNX2, which may be via the activation of the Wnt/β-catenin pathway. In vivo, combined treatment with rSMSC-EVs and ICA promoted cartilage repair in joint bone defects. Results also showed that ICA or rSMSC-EVs both promoted the COL2A1 and β-catenin protein accumulation in articular cartilage, and that was further enhanced by combined treatment with rSMSC-EVs and ICA.

Conclusion

Our findings highlight the promising potential of using combined treatment with ICA and rSMSC-EVs for promoting osteochondral repair.

Jiawei Yanghe Decoction attenuate allergic airway inflammation by suppressing group 2 innate lymphoid cells responses

ETHNOPHARMACOLOGICAL RELEVANCE

Jiawei Yanghe Decoction (JWYHD) is modified Yanghe Decoction (YHD). YHD historically utilized as a potent medicinal solution for addressing chronic inflammatory conditions, holds promising therapeutic potential in the treatment of asthma. However, the mechanisms underlying JWYHD's effects on allergic asthma remain unclear.

AIM OF THE STUDY

To investigate the therapeutic effect as well as the underlying mechanisms of JWYHD on asthmatic mice.

MATERIALS AND METHODS

The ovalbumin (OVA)-induced mouse model was utilized, followed by the administration of JWYHD to allergic asthmatic mice. Subsequently, inflammatory cells in the bronchoalveolar lavage fluid (BALF) and lung tissues were conducted. The levels of various cytokines including interleukin (IL)-4, IL-5, IL-13, IL-33, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in BALF, as well as the total immunoglobulin E (IgE) content in serum, were assessed. Lung function and tissue pathology examinations were performed to assess the protective impacts of JWYHD. The chemical components of JWYHD and its lung prototype compounds (referred to the chemical components present in JWYHD that were observed in the lung) were explored by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). RNA-seq analysis revealed the regulation mechanisms of JWYHD treating asthma. Furthermore, the effect of JWYHD on type 2 innate lymphoid cells (ILC2s) in asthmatic mice was detected by flow cytometry and Smart-RNA-seq analysis. Then molecular docking analysis was used to show the interaction between identified compounds and key targets.

RESULTS

JWYHD significantly attenuated the airway inflammation of asthmatic mice, reduced the levels of inflammatory cells in BALF, as well the levels of the cytokines IL-4, IL-5, IL-13, IL-33, and TNF-α in BALF and IgE in serum. Airway hyperresponsiveness (AHR) and lung inflammation infiltration were also alleviated by JWYHD. Moreover, RNA-seq analysis revealed that JWYHD attenuated airway inflammation in asthmatic mice via regulating immunity. Flow cytometry confirmed that JWYHD could inhibit ILC2 responses. ILC2 Smart-RNA-seq analysis showed that JWYHD impaired the inflammation reaction-related signaling pathways in ILC2s, and neuropilin-1 (Nrp1), endothelial transcription factor 3 (GATA3) and interleukin 1 receptor like protein 1 (ST2) might be the key targets. The molecular docking analysis investigating the connection between the primary targets and JWYHD's prototype compounds in the lung demonstrated that liquiritin apioside, icariin, glycyrrhizic acid, and uralsaponin B, identified through UPLC-Q-TOF/MS, exhibited significant affinity in binding to the mentioned key targets.

CONCLUSION

Our results suggested that the mechanism of JWYHD in treating asthma might be related to limiting ILC2 responses. Our findings provided some pharmacological evidence for the clinical application of JWYHD in the treatment of asthma.

Icariin accelerates bone regeneration by inducing osteogenesis-angiogenesis coupling in rats with type 1 diabetes mellitus

BACKGROUND

Icariin (ICA), a natural flavonoid compound monomer, has multiple pharmacological activities. However, its effect on bone defect in the context of type 1 diabetes mellitus (T1DM) has not yet been examined.

AIM

To explore the role and potential mechanism of ICA on bone defect in the context of T1DM.

METHODS

The effects of ICA on osteogenesis and angiogenesis were evaluated by alkaline phosphatase staining, alizarin red S staining, quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence. Angiogenesis-related assays were conducted to investigate the relationship between osteogenesis and angiogenesis. A bone defect model was established in T1DM rats. The model rats were then treated with ICA or placebo and micron-scale computed tomography, histomorphometry, histology, and sequential fluorescent labeling were used to evaluate the effect of ICA on bone formation in the defect area.

RESULTS

ICA promoted bone marrow mesenchymal stem cell (BMSC) proliferation and osteogenic differentiation. The ICA treated-BMSCs showed higher expression levels of osteogenesis-related markers (alkaline phosphatase and osteocalcin) and angiogenesis-related markers (vascular endothelial growth factor A and platelet endothelial cell adhesion molecule 1) compared to the untreated group. ICA was also found to induce osteogenesis-angiogenesis coupling of BMSCs. In the bone defect model T1DM rats, ICA facilitated bone formation and CD31hiEMCNhi type H-positive capillary formation. Lastly, ICA effectively accelerated the rate of bone formation in the defect area.

CONCLUSION

ICA was able to accelerate bone regeneration in a T1DM rat model by inducing osteogenesis-angiogenesis coupling of BMSCs.

Catalpol promotes articular cartilage repair by enhancing the recruitment of endogenous mesenchymal stem cells

Articular cartilage defect is challenged by insufficient regenerative ability of cartilage. Catalpol (CA), the primary active component of Rehmanniae Radix, could exert protective effects against various diseases. However, the impact of CA on the treatment of articular cartilage injuries is still unclear. In this study, full-thickness articular cartilage defect was induced in a mouse model via surgery. The animals were intraperitoneally injected with CA for 4 or 8 weeks. According to the results of macroscopic observation, micro-computed tomography CT (μCT), histological and immunohistochemistry staining, CA treatment could promote mouse cartilage repair, resulting in cartilage regeneration, bone structure improvement and matrix anabolism. Specifically, an increase in the expression of CD90, the marker of mesenchymal stem cells (MSCs), in the cartilage was observed. In addition, we evaluated the migratory and chondrogenic effects of CA on MSCs. Different concentration of CA was added to C3H10 T1/2 cells. The results showed that CA enhanced cell migration and chondrogenesis without affecting proliferation. Collectively, our findings indicate that CA may be effective for the treatment of cartilage defects via stimulation of endogenous MSCs.

Efficient production of icariin and baohuoside I from Epimedium Folium flavonoids by fungal α-L-rhamnosidase hydrolysing regioselectively the terminal rhamnose of epimedin C

Industrial application of icariin and baohuoside I has been hindered by the short supply to a great extent. In this work, a novel GH78 α-L-rhamnosidase AmRha catalyzed the bioconversion of low-value epimedin C in crude Epimedium Folium flavonoids (EFs) to icariin and baohuoside I was developed. Firstly, the high-level expression of AmRha in Komagataella phaffii GS115 attained an enzyme activity of 571.04 U/mL. The purified recombinant AmRha could hydrolyze α-1,2-rhamnoside bond between two rhamnoses (α-Rha(2 → 1)α-Rha) in epimedin C to produce icariin with a molar conversion rate of 92.3%, in vitro. Furtherly, the biotransformation of epimedin C to icariin by the recombinant Komagataella phaffii GS115 cells was also investigated, which elevated the EFs concentration by fivefold. In addition, biotransformation of epimedins A-C and icariin in the raw EFs to baohuoside I was fulfilled by a collaboration of AmRha and β-glucosidase/β-xylosidase Dth3. The results obtained here provide a new insight into the preparation of high-value products icariin and baohuoside I from cheap raw EFs.

The Immunosuppressive Niche Established with a Curcumin-Loaded Electrospun Nanofibrous Membrane Promotes Cartilage Regeneration in Immunocompetent Animals

Inflammatory cells mount an immune response against in vitro engineered cartilage implanted into immunocompetent animals, consequently limiting the usage of tissue-engineered cartilage to repair cartilage defects. In this study, curcumin (Cur)-an anti-inflammatory agent-was mixed with poly(lactic-co-glycolic acid) (PLGA) to develop a Cur/PLGA nanofibrous membrane with nanoscale pore size and anti-inflammatory properties. Fourier-transform infrared spectroscopy and high-performance liquid chromatography analyses confirmed the successful loading of Cur into the Cur/PLGA nanofibrous membrane. The results of the in vitro assay demonstrated the sustained release kinetics and enhanced stability of Cur in the Cur/PLGA nanofibrous membrane. Western blotting and enzyme-linked immunosorbent assay analyses revealed that the Cur/PLGA nanofibrous membrane significantly downregulated the expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α). A chondrocyte suspension was seeded into a porous PLGA scaffold, and the loaded scaffold was cultured for 3 weeks in vitro to engineer cartilage tissues. The cartilage was packed with the in vitro engineered Cur/PLGA nanofibrous membrane and subcutaneously implanted into rats to generate an immunosuppressive niche. Compared with those in the PLGA-implanted and pure cartilage (without nanofibrous membrane package)-implanted groups, the cartilage was well preserved and the inflammatory response was suppressed in the Cur/PLGA-implanted group at weeks 2 and 4 post-implantation. Thus, this study demonstrated that packaging the cartilage with the Cur/PLGA nanofibrous membrane effectively generated an immunosuppressive niche to protect the cartilage against inflammatory invasion. These findings enable the clinical translation of tissue-engineered cartilage to repair cartilage defects.