Mesenchymal stem cells derived from CHIR99021 and TGF­ß induction remained on the colicomentum and improved cardiac function of a rat model of acute myocardium infarction.

Human induced pluripotent stem cells (hiPSCs) have been regarded as a potential stem cell source for cell therapy. However, the production of cells with mesenchymal potential from hiPSCs through spontaneous differentiation is time consuming and laborious. In the present study, the combined use of the GSK-3 inhibitor CHIR99021 and TGF-ß was used to obtain mesenchymal stem cell (MSC)-like cells from hiPSCs. During the induction process, the transcription of epithelial-mesenchymal transition (EMT)-related genes N-cadherin and Vimentin in the transformed cells was upregulated, whereas the transcription of E-cadherin and pluripotency-related transcription factors SOX2, OCT4 and NANOG did not change significantly. This indicated that whilst cells were pluripotent, EMT was initiated by the upregulation of transcription of EMT promoting genes. Both SMAD-dependent and independent signalling pathways were significantly activated by the combined induction treatment compared with the single factor induction. The hiPSC-derived MSC-like cells (hiPSC-MSCs) expressed MSC-related markers and acquired osteogenic, chondrogenic and adipogenic differentiation potentials. After being injected into the peritoneal cavity of rats, the hiPSC-MSCs secreted angiogenic and immune-regulatory factors and remained on the colicomentum for 3 weeks. Within an 11-week period, four intraperitoneal hiPSC-MSC injections (1x107 cells/injection) into acute myocardial infarction (AMI) model rats significantly increased the left ventricular ejection fraction, left ventricular fractional shortening and angiogenesis and significantly reduced scar size and the extent of apoptosis in the infarcted area compared with that of the control PBS injection. Symptoms of hiPSC-MSC-induced immune reaction or tumour formation were not observed over the course of the experiment in the hiSPC-MSC treated rats. In conclusion, the CHIR99021 and TGF-ß combined induction was a rapid and effective method to obtain MSC-like cells from hiPSCs and multiple high dose intraperitoneal injections of hiPSC-derived MSCs were safe and effective at restoring cardiac function in an AMI rat model.

MnO2/Ce6 microbubble-mediated hypoxia modulation for enhancing sono-photodynamic therapy against triple negative breast cancer.

Sono-photodynamic therapy (SPDT) has emerged as a promising treatment modality for triple negative breast cancer (TNBC). However, the hypoxic tumor microenvironment hinders the application of SPDT. Herein, in this study, a multifunctional platform (MnO2/Ce6@MBs) was designed to address this issue. A sono-photosensitizer (Ce6) and a hypoxia modulator (MnO2) were loaded into microbubbles and precisely released within tumor tissues under ultrasound irradiation. MnO2in situ reacted with the excess H2O2 and H+ and produced O2 within the TNBC tumor, which alleviated hypoxia and augmented SPDT by increasing ROS generation. Meanwhile, the reaction product Mn2+ was able to achieve T1-weighted MRI for enhanced tumor imaging. Additionally, Ce6 and microbubbles served as a fluorescence imaging contrast agent and a contrast-enhanced ultrasound imaging agent, respectively. In in vivo anti-tumor studies, under the FL/US/MR imaging guidance, MnO2/Ce6@MBs combined with SPDT significantly reversed tumor hypoxia and inhibited tumor growth in 4T1-tumor bearing mice. This work presents a theragnostic system for reversing tumor hypoxia and enhancing TNBC treatment.

Correction: MnO2/Ce6 microbubble-mediated hypoxia modulation for enhancing sono-photodynamic therapy against triple negative breast cancer.

Correction for 'MnO2/Ce6 microbubble-mediated hypoxia modulation for enhancing sono-photodynamic therapy against triple negative breast cancer' by Ping Li et al., Biomater. Sci., 2024, https://doi.org/10.1039/d3bm00931a.

Delivery of hydroxycamptothecin via sonoporation: An effective therapy for liver fibrosis.

Hepatic fibrosis is the common pathway for most chronic liver diseases, characterized by excessive accumulation of extracellular matrix (ECM) proteins. It has been shown that fibrotic ECM significantly hindered passage of nanoparticles. Efforts have been made by decorating degrading enzymes on surfaces of nanosized delivery vehicles to improve drug delivery. However, these strategies are restricted by limiting shelf-life. Inspired by the application of sonoporation in assisting drug delivery through blood-brain barrier and tumor tissues, we investigated whether sonoporation can be an alternative strategy in improving drug delivery for fibrotic diseases. Hydroxycamptothecin (HCPT), a potential drug in treating liver fibrosis, was selected as a model drug to evaluate the drug delivery efficiency and therapeutic effect among three delivery strategies, i.e., (1) injection solution, (2) delivery through liposomes, and (3) delivery via sonoporation. Our study showed that in addition to the improved drug delivery efficiency, the combination of HCPT and sonoporation led to synergistic effect and the mechanisms were investigated. The treatment group of HCPT delivered with sonoporation achieved the most significant attenuation in liver fibrosis among the three delivery strategies.

Ultrasound combined with glial cell line-derived neurotrophic factor-loaded microbubbles for the targeted treatment of drug addiction.

Drug addiction is a serious problem globally, recently exacerbated by the COVID-19 pandemic. Glial cell-derived neurotrophic factor (GDNF) is considered a potentially effective strategy for the treatment of addiction. Previous animal experiments have proven that GDNF has a good therapeutic effect on drug addiction, but its clinical application is limited due to its poor blood-brain barrier (BBB) permeability. Low-frequency focused ultrasound, combined with microbubbles, is a non-invasive and reversible technique for locally-targeted BBB opening. In the present study, magnetic resonance imaging-guided low-frequency focused ultrasound, combined with GDNF microbubbles, was used to target BBB opening in the ventral tegmental area (VTA) region. The effects of GDNF on morphine-induced conditioned place preference (CPP) and acute withdrawal symptoms in rats after a partially opened BBB were evaluated by behavioral observation. Western blot was used to detect changes in tyrosine hydroxylase (TH) expression levels in the VTA region after different treatments, and high performance liquid chromatography was used to detect the changes in monoamine neurotransmitter content. The results showed that ultrasound combined with GDNF microbubbles targeted and opened the BBB in the VTA region, and significantly increased GDNF content, destroyed morphine-induced CPP, and reduced the withdrawal symptoms of morphine addiction in rats. Furthermore, the up-regulation of TH expression and the increase of norepinephrine and dopamine content induced by morphine were significantly reversed, and the increase of 5-hydroxytryptamine content was partially reversed. Therefore, ultrasound combined with GDNF microbubbles to target and open the BBB can effectively increase the content of central GDNF, thus playing a therapeutic role in morphine addiction. Our study provides a new approach to locally open the BBB and target delivery of neurotrophic factors, such as GDNF, to treat brain diseases like addiction.

Lipidated Methotrexate Microbubbles: A Promising Rheumatoid Arthritis Theranostic Medicine Manipulated via Ultrasonic Irradiation.

De novo designed lipidated methotrexate was synthesized and self-assembled into microbubbles for targeted rheumatoid arthritis theranostic treatment. Controlled lipidatedmethotrexate delivery was achieved by ultrasound-targetedmicrobubble destruction technique. Methotrexate was dissociated inflammatory microenvironment of synovial cavity, owing to representive low pH and enriched leucocyte esterase. We first manipulated methotrexate controlled release with RAW 264.7 cell line in vitro and further verified with rheumatoid arthritis rabbits in vivo. Results showed that lipidated methotrexate microbubbles precisely affected infection focus and significantly enhanced rheumatoid arthritis curative effect comparing with dissociative methotrexate. This study indicates that lipidated methotrexate microbubbles might be considered as a promising rheumatoid arthritis theranostics medicine.

Berberine nanoparticles for promising sonodynamic therapy of a HeLa xenograft tumour.

Here, we show that berberine (BBR) nanoparticles (BBRNPs, ∼300 nm hydrodynamic diameter) are a promising sonosensitizer for cancer sonodynamic therapy (SDT). HeLa cells were cultured for in vitro investigation, and a HeLa xenograft tumor model was established with BALB/c nude mice (∼20 g, female) for in vivo study. Significant effects of BBRNP-mediated SDT were observed in both in vitro and in vivo experiments. Cell counting kit-8 (CCK-8) cell proliferation and cytotoxicity assays were performed to confirm if BBRNPs-SDT has cytotoxicity against HeLa cells in vitro. The mechanism for inhibition of tumor proliferation by BBRNPs-SDT was investigated via flow cytometry, photoluminescence spectroscopy, dynamic light scattering, scanning electron microscopy, ultrasonic contrast imaging, tumour pathological analysis, western blot and anatomical analysis. We identified two ongoing assumptive mechanisms. One is due to the tumor angioembolism effect, which blocks oxygen and nutrient supply in situ, leading to early-stage HeLa apoptosis. The other domino effect is due to ultrasonic energy-activated BBRNP cavitation and reactive oxygen species release, which leads to tumor vascular injury and finally induces HeLa apoptosis, resulting in tumour shrinkage. Both pathways synergistically helped with HeLa xenograft tumor supression. In conclusion, we posit that BBRNPs are a promising agent for tumor SDT.

Transfection of neurotrophin-3 into neural stem cells using ultrasound with microbubbles to treat denervated muscle atrophy.

Neurotrophin-3 (NT-3) has potential as a therapeutic agent for the treatment of patients with denervated muscle atrophy. However, the endogenous secretion of NT-3 is low and exogenous NT-3 lacks sufficient time to accumulate due to its short half-life. The transfection of NT-3 has been demonstrated to have a beneficial effect on denervated muscle and motor endplates. Neural stem cells (NSCs) differentiate into neurons and form motor endplate nerve-muscle connections. It has been previously demonstrated that local and noninvasive transfection can be performed using ultrasound with microbubbles (MBs). In the current study, hematoxylin and eosin, acetylcholinesterase and gold chloride staining, as well as transmission electron microscopy, were performed to verify the effects of this treatment strategy. The results demonstrated that using ultrasound with MBs for the transfection of NT-3 into NSCs, and their subsequent transplantation in vivo, attenuated the atrophy of denervated muscle and reduced motor endplate degeneration. This noninvasive, efficient and targeted treatment strategy may therefore be a potential treatment for patients with denervated muscle atrophy.