Mesenchymal Stem Cells-Derived Extracellular Vesicles Mimetics as Osteoinductive Mediators for Bone Healing

AUTHORS

Antoine Karoichan, Ling Li, Celine J. Agnes, Bettina M. Willie, Maryam Tabrizian

ABSTRACT

Bone defects remain challenging to treat, with common therapies still relying on invasive approaches. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) offer a promising alternative due to their regenerative and immunomodulatory properties, but challenges in scalable EV production limit clinical translation. Nanoghosts (NGs) are an emerging class of EV-mimetics synthesized through the physical distortion of ghost cells that offer innate bioactivity similar to EVs while having more scalable yields. In this study, the osteogenic potential of NGs made from MSC ghosts (MSC-NGs) is explored for the first time and contrasted with conventional MSC-EVs. MSC-NGs are generated through sonication, yielding two-fold more vesicles compared to MSC-EVs from the same number of cells. Unlike MSC-EVs, MSC-NGs significantly enhanced the osteogenic differentiation of MSCs, evidenced by increased alkaline phosphatase (ALP) activity and early mineralization. Proteomic analysis further revealed that MSC-NGs are more enriched in osteogenesis-related proteins than MSC-EVs. In vivo, treatment of a 0.5 mm mouse femoral osteotomy with MSC-NGs accelerated fracture healing, showing increased callus mineralization by day 14 and improved bone marrow reconstitution by day 21, along with reduced osteoclastic activity. These findings demonstrate MSC-NGs as scalable and effective therapeutics for bone tissue engineering, offering advantages over MSC-EVs in future bone healing strategies.

Bone Marrow Stem Cell Population in Single- and Multiple-Level Aspiration

AUTHORS

Xiangguo Che, Hee-June Kim, Xian Jin, Joon-Woo Kim, Kyeong-Hyeon Park, Jeong-Ok Lim, Hee-Soo Kyung, Chang-Wug Oh, Je-Yong Choi

ABSTRACT

Background: Bone marrow aspiration concentrate (BMAC) has garnered increasing interest due to its potential for healing musculoskeletal injuries. While the iliac crest remains a common harvest site, the aspiration technique’s efficacy in offering the highest yield and prevalence of mesenchymal stem cells (MSCs) is controversial. This study aimed to compare two different techniques of bone marrow aspiration over the anterior iliac crest from a single level versus multiple levels. Methods: Anterior iliac crests were selected in seven adult patients (aged between 31 and 59 years old). Aspiration was achieved using an 11-gauge needle (length: 100 mm; diameter: 2.3 mm) specifically manufactured for bone marrow collection (BD, Becton, Franklin Lakes, NJ, USA) connected to a 10 mL syringe. On one side, 4cc of bone marrow was aspirated at a single level to a depth of 7 cm without changing the needle direction. On the other side, over the same portion of the iliac crest, 1 cc of bone marrow was obtained from multiple levels of different depths during needle retrieval, maintaining a distance of 1 cm and changing the tip direction. The samples were blindly sent to the laboratory without indicating whether they came from an single level or multiple levels. Fluorescence-activated cell sorting (FACS) and osteoblast differentiation were analyzed and compared. Results: In the FACS analysis, the single level resulted in a higher population of MSCs that were positive for CD105, CD73, and CD90 and negative for CD34, compared to the multiple-level method. In the process of osteoblast differentiation, it was observed that MSCs exhibited more advanced features of enhanced osteoblastic abilities in the single-level method rather than the multiple-level method. Conclusions: A single-level aspiration technique at the anterior iliac crest may produce a high-quality bone marrow aspirate. This technique may help obtain specific populations of MSCs with the desired characteristics for use in regenerative therapies for musculoskeletal injuries.

Mesenchymal stromal cell extracellular vesicles improve lung development in mechanically ventilated preterm lambs

AUTHORS

Kurt H. Albertine, Andrew Rebentisch, Elaine Dawson, Jakob Van Boerum, Emily Major, Juraj Štipka, Hannah Foreman, David Headden, Zoë Vordos, Emily Beck, Zhengming Wang, Haixia Yang, Baifeng Yu, Mar Janna Dahl, Donald M. Null, Davide Bizzotto, Chiara Veneroni, Anna Lavizzari, Raffaele L. Dellacà, Eleni Delavogia, S. Alex Mitsialis, Stella Kourembanas

ABSTRACT

Novel therapies are needed for bronchopulmonary dysplasia (BPD) because no effective treatment exists. Mesenchymal stromal cell extracellular vesicles (MSC-sEVs) have therapeutic efficacy in a mouse pup neonatal hyperoxia BPD model. We tested the hypothesis that MSC-sEVs will improve lung functional and structural development in mechanically ventilated preterm lambs. Preterm lambs (∼129 days; equivalent to human lung development at ∼28 wk gestation) were exposed to antenatal steroids, surfactant, caffeine, and supported by mechanical ventilation for 6–7 days. Lambs were randomized to blinded treatment with either MSC-sEVs (human bone marrow MSC-derived; 2 × 1011 particles iv; n = 8; 4 F/4 M) or vehicle control (saline iv; 4 F/4 M) at 6 and 78 h post delivery. Physiological targets were pulse oximetry O2 saturation 90–94% (P⁢aO2

60–90 mmHg), P⁢aC⁢O2

45–60 mmHg (pH 7.25–7.35), and tidal volume 5–7 mL/kg. MSC-sEVs-treated preterm lambs tolerated enteral feedings compared with vehicle control preterm lambs. Differences in weight patterns were statistically significant. Respiratory severity score, oxygenation index, A-a gradient, distal airspace wall thickness, and smooth muscle thickness around terminal bronchioles and pulmonary arterioles were significantly lower for the MSC-sEVs group. S/F ratio, radial alveolar count, secondary septal volume density, alveolar capillary surface density, and protein abundance of VEGF-R2 were significantly higher for the MSC-sEVs group. MSC-sEVs improved respiratory system physiology and alveolar formation in mechanically ventilated preterm lambs. MSC-sEVs may be an effective and safe therapy for appropriate functional and structural development of the lung in preterm infants who require mechanical ventilation and are at risk of developing BPD.

NEW & NOTEWORTHY This study focused on potential treatment of preterm infants at risk of developing bronchopulmonary dysplasia (BPD), for which no effective treatment exists. We tested treatment of mechanically ventilated preterm lambs with human mesenchymal stromal cell extracellular vesicles (MSC-sEVs). The results show improved respiratory gas exchange and parenchymal growth of capillaries and epithelium that are necessary for alveolar formation. Our study provides new mechanistic insight into potential efficacy of MSC-sEVs for preterm infants at risk of developing BPD.

Apoptotic Vesicles Regulate Bone Metabolism via the miR1324/SNX14/SMAD1/5 Signaling Axis

AUTHORS

Yuan Zhu, Kunkun Yang, Yawen Cheng, Yaoshan Liu, Ranli Gu, Xuenan Liu, Hao Liu, Xiao Zhang, Yunsong Liu

ABSTRACT

Mesenchymal stem cells (MSCs) are widely used in the treatment of diseases. After their in vivo application, MSCs undergo apoptosis and release apoptotic vesicles (apoVs). This study investigates the role of apoVs derived from human bone marrow mesenchymal stem cells (hBMMSCs) in bone metabolism and the molecular mechanism of the observed effects. The results show that apoVs can promote osteogenesis and inhibit osteoclast formation in vitro and in vivo. ApoVs may therefore attenuate the bone loss caused by primary and secondary osteoporosis and stimulate bone regeneration in areas of bone defect. The mechanisms responsible for apoV-induced bone regeneration include the release of miR1324, which inhibit expression of the target gene Sorting Nexin 14 (SNX14) and thus activate the SMAD1/5 pathway in target cells. Given that MSC-derived apoVs are easily obtained and stored, with low risks of immunological rejection and neoplastic transformation, The findings suggest a novel therapeutic strategy to treat bone loss, including via cell-free approaches to bone tissue engineering.

Apoptotic Vesicles Regulate Bone Metabolism via the miR1324/SNX14/SMAD1/5 Signaling Axis

AUTHORS

Yuan Zhu, Kunkun Yang, Yawen Cheng, Yaoshan Liu, Ranli Gu, Xuenan Liu, Hao Liu, Xiao Zhang, Yunsong Liu

ABSTRACT

Mesenchymal stem cells (MSCs) are widely used in the treatment of diseases. After their in vivo application, MSCs undergo apoptosis and release apoptotic vesicles (apoVs). This study investigates the role of apoVs derived from human bone marrow mesenchymal stem cells (hBMMSCs) in bone metabolism and the molecular mechanism of the observed effects. The results show that apoVs can promote osteogenesis and inhibit osteoclast formation in vitro and in vivo. ApoVs may therefore attenuate the bone loss caused by primary and secondary osteoporosis and stimulate bone regeneration in areas of bone defect. The mechanisms responsible for apoV-induced bone regeneration include the release of miR1324, which inhibit expression of the target gene Sorting Nexin 14 (SNX14) and thus activate the SMAD1/5 pathway in target cells. Given that MSC-derived apoVs are easily obtained and stored, with low risks of immunological rejection and neoplastic transformation, The findings suggest a novel therapeutic strategy to treat bone loss, including via cell-free approaches to bone tissue engineering.