Human pluripotent stem cell-derived cardiomyocytes offer an ideal cellular resource for studying heart diseases, conducting drug screening, developing in vitro heart models, and exploring potential cell therapies. However, human pluripotent stem cell-derived cardiomyocytes are characterized by immaturity with limited specific gene expression, low Ca²⁺ processing levels, and underdeveloped structural, metabolic, and electrophysiological features. These limitations significantly impede the application of human pluripotent stem cell-derived cardiomyocytes.

To review the academic progress and clinical application of promoting the maturation of human pluripotent stem cell-derived cardiomyocytes by in vitro synthetic microenvironment.

CNKI, WanFang, VIP, PubMed, Web of Science, and Medline databases were searched, with “human pluripotent stem cells, human myocardial cells, hPSC-CMs, mature, OA, human pluripotent stem cell-derived cardiomyocytes, hPSC-CMs” as English search terms and “human pluripotent stem cells, cardiomyocytes, mature, OA, hPSC-CMs” as Chinese search terms. All relevant literature published from January 2002 to July 2024 was retrieved and 82 articles were included in the review.

(1) In recent years, in vitro synthetic microenvironments have attracted extensive attention due to their excellent intrinsic properties such as stiffness, plasticity, nanoscale morphology, and chemical functionality. (2) Human pluripotent stem cell-derived cardiomyocytes can be used as an effective platform for the treatment of cardiovascular diseases. (3) Mechanical stimulation, electrical stimulation, addition of biochemical molecules, and three-dimensional culture methods are effective methods to promote the maturation of human pluripotent stem cell-derived cardiomyocytes, which can further promote the clinical application of human pluripotent stem cell-derived cardiomyocytes.

Stem cells from human exfoliated deciduous teeth are widely used in the field of tissue repair and regeneration, but the tissue regeneration effect has limitations in practical applications. Using miRNA to intervene in the directional differentiation of stem cells from human exfoliated deciduous teeth is an important development direction for tissue repair and regeneration in the future.

To investigate the effect of miR-26b on the neurogenic and angiogenic differentiation of stem cells from human exfoliated deciduous teeth.

Dental pulp stem cells were isolated and extracted from human exfoliated deciduous teeth, and induced to differentiate into nerves and blood vessels. The expressions of neurogenic markers Nestin, NSE, βIII-Tubulin, and angiogenic markers CD31, VEGFR2, ANG-1 and miR-26b were detected. Dental pulp stem cells were divided into blank control group, miR-26 overexpression group, and negative control group. RT-qPCR, cell immunofluorescence staining, and western blot assay were used to detect the expression changes of related markers of neurogenic and angiogenic induction of stem cells from human exfoliated deciduous teeth in each group.

(1) Stem cells from human exfoliated deciduous teeth had multi-directional differentiation potential and could differentiate into osteogenesis, adipogenesis, neurogenesis, and vasculogenesis. (2) The expression level of miR-26b increased during the neurogenic and angiogenic differentiation of stem cells from human exfoliated deciduous teeth. (3) Compared with the blank control group and negative control group, the mRNA expression of neuroblast-related genes βIII-Tubulin, Nestin, NSE and angiogenesis-related genes CD31, VEGFR2, and ANG-1 in stem cells from human exfoliated deciduous teeth in the miR-26b overexpression group was significantly increased (P < 0.01), βIII-Tubulin, Nestin, CD31, and VEGFR2 protein expression was significantly increased (P < 0.01). The above results show that overexpression of miR-26b can promote the neurogenic and angiogenic differentiation of stem cells from human exfoliated deciduous teeth.

Bone marrow mesenchymal stem cells are the main effector cells for bone formation. With the increase of age, the regenerative ability of bone marrow mesenchymal stem cells is weakened and the differentiation function is impaired, leading to poor osteoporosis. Therefore, restoring the regenerative capacity and cellular function of aged bone marrow mesenchymal stem cells is essential for the effective treatment of osteoporosis.

To investigate the effects of passage 3 and passage 11 bone marrow mesenchymal stem cells-derived exosomes of young rats on the aging of bone marrow mesenchymal stem cells derived from elderly rats.

Bone marrow mesenchymal stem cells from 6-8-week-old female SD rats were isolated and cultured, and passaged to the passages 3 and 11, respectively. Then, exosomes from passages 3 and 11 bone marrow mesenchymal stem cells were extracted. Bone marrow mesenchymal stem cells from 18-month-old female SD rats were isolated and cultured, passaged to passage 3, and divided into 3 groups. The control group was routinely cultured, and the other two groups were intervened with exosomes from passages 3 and 11 bone marrow mesenchymal stem cells. After 48 hours of exosome intervention, the expression of β-galactosidase in the nucleus was detected by β-galactosidase staining kit. The expression of aging-related genes was detected by qRT-PCR. The expression differences of miRNA in exosomes from passages 3 and 11 bone marrow mesenchymal stem cells were compared by Small RNA sequencing.

(1) Compared with the control group and passage 11 bone marrow mesenchymal stem cell-derived exosomes group, the β-galactosidase activity of bone marrow mesenchymal stem cells of aged rats was significantly lower in the passage 3 bone marrow mesenchymal stem cell-derived exosomes group. (2) Compared with the control group, the expression of aging-related genes p21 and p16 was significantly reduced in the passage 3 bone marrow mesenchymal stem cell-derived exosome group (P < 0.05), while there was no significant difference in the expression of aging-related genes p21 and p16 in the passage 11 bone marrow mesenchymal stem cell-derived exosome group. (3) Sequencing results showed that there was a significant difference in the expression of miRNAs in the two exosomes, among which the miRNAs with the most significant expression differences were let-7c-5p, let-7b-5p, miR-320-3p, and miR-26a-5p. KEGG analysis results showed that significantly different miRNA enrichment pathways include mTOR, AMPK and other aging-related signaling pathways. The above results indicate that passage 3 bone marrow mesenchymal stem cell-derived exosomes have the ability to reverse the aging of bone marrow mesenchymal stem cells in aged rats.

Extracellular vesicles have received extensive attention in the field of bone defect regeneration and repair in recent years. However, natural extracellular vesicles have deficiencies in sustained controlled release, tissue targeting, and drug loading capacity. Therefore, the introduction of engineering strategies to modify extracellular vesicles to enhance their therapeutic efficacy has become a research hotspot.

To review the role and application progress of engineered extracellular vesicles in the regeneration and repair of bone defects.

PubMed, Web of Science, CNKI, and WanFang databases were searched for relevant articles published in the past fifteen years. The search terms were “engineering, extracellular vesicles, exosomes, bone defect, bone regeneration, bone repair” in Chinese and English. After removal of poorly related, outdated, and duplicate studies by screening, 93 articles were finally included for review according to inclusion criteria.

(1) Extracellular vesicles are primarily isolated based on their density, size, immunoaffinity, and surface charge. After isolation, extracellular vesicles are characterized using imaging techniques, size- and counting-based techniques, and flow cytometry. (2) Extracellular vesicles stimulate bone regeneration by regulating immunity, angiogenesis, and proliferation and differentiation of target cells. (3) The engineering strategies of extracellular vesicles include surface modification and cargo loading. (4) The introduction of bone morphogenetic protein 2, mutant hypoxia-inducible factor-1α, vascular endothelial growth factor, miRNA and other bioactive factors into extracellular vesicles through engineering strategies can enhance their regenerative repair ability for bone defects.

Human umbilical cord mesenchymal stem cell-derived exosomes were found to be effective in promoting neural repair in spinal cord injury.

To investigate whether exosomes derived from human umbilical cord mesenchymal stem cells are able to attenuate neuroinflammation and promote recovery of motor function by promoting polarization of microglia toward the M2 type.

Totally 48 SD rats were randomly divided into a sham operation group, a model group, and an exosome group (n=16 per group). A rat spinal cord injury model was established using the modified Allen method. The exosome group was injected with 20 μL of human umbilical cord mesenchymal stem cell-derived exosomes intrathecally via neuroendoscopy 24 hours after injury. At 3, 7, 14, and 21 days after modeling, the recovery of the motor function of the hind limbs of the rats was assessed by BBB scoring method combined with Rivlin's slant plate test. The damage of spinal cord tissues was detected by using hematoxylin-eosin staining and Nissl staining. The expression levels of brain-derived neurotrophic factor and vascular endothelial growth factor A proteins were detected by western blot assay. The expression proportion of M1-type markers (inducible nitric oxide synthase) and M2 markers (arginase-1) in the spinal cord tissues was detected by immunofluorescence method. qRT-PCR and western blot assay were used to detect the expression levels of inducible nitric oxide synthase and arginase-1 in spinal cord tissues. ELISA was utilized to detect the levels of pro-inflammatory factors (tumor necrosis factor α, interleukin 1β, and interleukin 6) and anti-inflammatory factors (interleukin 10) levels in spinal cord tissues.

(1) At 3, 7, and 14 days postoperatively, the BBB scores of the exosome group were better than those of the model group (P < 0.05). The angles of the Rivlin slanting plate experiments of the exosome group were significantly higher than those of the model group at 7 and 14 days postoperatively (P < 0.05). The results of hematoxylin-eosin staining and Nissl staining indicated that the spinal cord tissues and nerve injuries of the exosome group were reduced in comparison with those of the model group, and the levels of brain-derived neurotrophic factor and vascular endothelial growth factor A in spinal cord tissues of the exosome group were higher than those in the model group at 7 days postoperatively (P < 0.05). (2) Immunofluorescence experiments showed that the number of inducible nitric oxide synthase-positive microglial cells in the lesion area of the exosome group was significantly reduced and the level of Arg1-positive microglial cells increased in the lesion area of the exosome group compared with the model group at 7 days postoperatively (P < 0.05). qRT-PCR and western blot assay also confirmed the results of immunofluorescence experiments. (3) The secretion of pro-inflammatory factors tumor necrosis factor α, interleukin 1β, and interleukin 6 in spinal cord tissues of the exosome group was reduced compared with the model group (P < 0.05), whereas the secretion of the inflammation-suppressing factor interleukin 10 was increased compared with the model group (P < 0.05). These findings conclude that human umbilical cord mesenchymal stem cell-derived exosomes could promote the polarization of microglial cells from the M1 to the M2 type and decrease the release of pro-inflammatory factors, thereby reducing the secondary damage of neuroinflammation in spinal cord injury.

Previous studies have shown that Huosui Formula has a synergistic effect on the immune and hematopoietic regulation of patients with myelodysplastic syndrome, but the specific mechanism is not yet clear.

To explore the effect and mechanism of Huosui Formula on bone marrow hematopoiesis in rats with myelodysplastic syndrome.

A total of 70 SD rats were randomly divided into a normal control group (n=10), a model group (n=15), a western medicine group (n=15), a low-dose Huosui Formula group (n=15), and a high-dose Huosui Formula group (n=15). Except for the normal control group, the other four groups were injected with dimethylbenzanthracene via the tail vein to induce the establishment of rat myelodysplastic syndrome models. After modeling, the normal control group and the model group were given normal saline; the western medicine group was given thalidomide capsules 10 mg/kg and retinoic acid tablets 4 mg/kg, and the low-dose Huosui Formula group and the high-dose Huosui Formula group were given 1.5 and 6 g/kg Huosui Formula, respectively, by intragastric administration once a day for 28 consecutive days. Peripheral blood and femoral bone marrow tissue were collected to detect peripheral blood routine and bone marrow biopsy hematopoietic proliferation. Flow cytometry was used to detect T lymphocyte subsets and the expression of CTLA-4 and PD-1 on T lymphocytes.

(1) Compared with the normal control group, peripheral blood leukocyte, neutrophil, hemoglobin, platelet, and CD4⁺, CD4⁺/CD8⁺ levels were decreased in the model group significantly (P < 0.05), while CD4⁺PD-1⁺, CD8⁺PD-1⁺, CD4⁺CTLA-4⁺, and CD8⁺CTLA-4⁺ expressions were significantly upregulated (P < 0.05). (2) In all dosage groups, myelopoietic proliferation was increased compared with the model group, with no significant difference between the groups (P > 0.05). (3) Compared with the model group, leukocytes, hemoglobin, platelets, and CD4⁺, CD4⁺/CD8⁺ were significantly elevated in the high-dose Huosui Formula group (P < 0.05), the expression of CD8⁺ was significantly lower (P < 0.05), and the levels of CD4⁺PD-1⁺, CD8⁺PD-1⁺, CD4⁺CTLA-4⁺, and CD8⁺CTLA-4⁺ were down-regulated but not statistically significant (P > 0.05). (4) The western medicine group and the high-dose Huosui Formula group showed similar efficacy. The improvement of each index in the high-dose Huosui Formula group was superior to that in the low-dose Huosui Formula group. These findings indicate that Huosui Formula can improve the bone marrow hematopoiesis in myelodysplastic syndrome model rats, increase the levels of CD4⁺, and CD4⁺/CD8⁺ while down-regulate the expression levels of CD4⁺PD-1⁺, CD8⁺PD-1⁺, CD4⁺CTLA-4⁺, and CD8⁺CTLA-4⁺. These observations suggest a link to the negative immunoregulation mechanism.

Numerous studies have indicated that pyroptosis plays a key role in the progression of cancer. In recent years, research has shown that pyroptosis is inextricably linked to the occurrence, development, and treatment of breast cancer. The development of effective pyroptosis-based therapeutic strategies has become a hot topic in the field of breast cancer treatment.

To comprehensively analyze the mechanisms of pyroptosis, explore the role of pyroptosis in the anti-tumor effects in breast cancer, and its potential application value in clinical treatment.

Using English search terms “pyroptosis, breast cancer, inflammasome, gasdermin, caspase, drug resistance, treatment”, PubMed database was searched for articles published from inception to August 2024. Through the preliminary screening of reading titles and abstracts, literature with poor relevance to the research content, outdated information, repeated views, and lack of authority was excluded. Finally, 121 articles were included for review.

Pyroptosis is a special form of programmed cell death that is carried out by the activation of the gasdermin family of proteins, showing potential application value in the treatment of breast cancer. Long-term or improper treatment can lead to drug resistance in cancer cells; research on the mechanism of pyroptosis helps to overcome resistance deficiencies. Pyroptosis can trigger immunogenic cell death, promoting the release of tumor-specific antigens, thereby activating the immune system and enhancing its ability to recognize and clear tumor cells. The expression levels of pyroptosis-related genes can serve as prognostic indicators for breast cancer, helping to assess patients’ treatment responses and survival periods. Research on the mechanisms of pyroptosis can provide new strategies for the treatment of breast cancer, such as targeted drugs and therapeutic methods that induce pyroptosis, contributing to the realization of personalized treatment plans for breast cancer.

The cryopreservation technology enables tissues/cells to be stored for a long time in a low-temperature environment while maintaining the integrity of their activity and function, which is of great significance for the construction of cell therapy, tissue engineering and biological sample banks. Cryoprotective agents often contain dimethyl sulfoxide and serum. To avoid the toxic side effects of dimethyl sulfoxide, the complexity of serum components and immune responses, although some finished cryoprotective agents have been marketed, they are faced with many difficulties such as high cost and limited application. Therefore, there is an urgent need to develop a cryoprotective agent with clear components and the ability to solve the above problems.

To evaluate the effects of a novel cryoprotectant on cryopreservation efficiency of different tissue and cell sources.

By applying the novel cryoprotectant as an experimental group with the commercially available and widely used cryoprotectant (control group) to umbilical cord Wharton's jelly tissue, umbilical cord mesenchymal stem cells, umbilical cord blood/peripheral blood mononuclear cells, NK and CIK cells, comparative analyses were conducted in terms of cell morphology, number, viability, surface markers, differentiation potential, and cell-killing toxicity assay before cryopreservation and after resuscitation thawing. We confirmed the cryopreservation effect of the new cryoprotectant and its potential application value.

(1) The novel cryoprotectant facilitated the normal growth of cryopreserved Wharton's jelly tissue upon recovery, exhibiting mesenchymal stem cell morphology. No significant differences were observed between the experimental and control groups in terms of cell recovery rate, surface markers, and differentiation potential. (2) There was no significant difference in the number and viability of cells between the experimental group and the control group after cryopreservation of cord blood/peripheral blood mononuclear cells, and the cryo-resuscitated cell numbers and viability of derived NK cells/CIK cells did not show significant difference between the experimental and control groups. (3) For NK cells derived and differentiated from cord blood/peripheral blood mononuclear cells, there was no significant difference in the proportion of CD56⁺CD16⁺ cell subpopulations between the experimental group and the control group. For CIK cells derived and differentiated from cord blood/peripheral blood mononuclear cells, there was no significant difference in the proportions of CD3⁺CD8⁺ and CD3⁺CD56⁺ cell subpopulations between the experimental group and the control group. (4) In terms of cytotoxicity testing, when the effective-target ratio of immune cells and melanoma cell line Mel624 was 20:1, whether it was NK cells/CIK cells derived from cord blood or peripheral blood mononuclear cells, there was no significant difference in the tumoricidal activity of cells between the experimental group and the control group. These findings suggest that the novel cryoprotectant can replace existing commercially available and widely used cryoprotectants, and is applicable to Wharton's jelly tissue, umbilical cord mesenchymal stem cells, umbilical cord blood/peripheral blood mononuclear cells, as well as NK and CIK cells, providing a solid technical foundation for the scaling, standardization, and commercialization of universal cryoprotectants.

Hematopoietic stem cell transplantation is a widely used treatment method to cure malignant and nonmalignant diseases originated from hematological cells. Mobilization and collection of sufficient hematopoietic stem cells are the preconditions to ensure rapid and sustained hematopoietic reconstitution after hematopoietic stem cell transplantation. However, the most commonly used granulocyte colony-stimulating factor with or without chemotherapy still has a mobilization failure rate of 10% to 40%.

To review the present status of hematopoietic stem cell mobilization in recent years, analyze the advantages and disadvantages of different mobilization plans, and be looking forward for new mobilization methods.

Using “hematopoietic stem cell, hematopoietic stem cell transplantation, hematopoietic stem cell mobilization, cytokines, thrombopoietin, CXCR4 antagonists, integrin antagonist, chemotherapy, mobilization efficiency” as Chinese and English keywords, articles published from 1990 to 2024 were searched on CNKI, PubMed, and WanFang databases. A total of more than 300 articles were retrieved, and 68 articles were finally included.

More and more studies have found that granulocyte colony-stimulating factor combined with other agents including plerixafor, interleukins, thrombopoietin, and integrin antagonist could improve hematopoietic stem cell mobilization. Combined use can reduce the dose of granulocyte colony-stimulating factor and related adverse reactions. Some new drugs, such as soluble recombinant FLT3-ligand (CDX-301) and dual α9β1/α4β1 integrin inhibitor BOP, can be combined with granulocyte colony-stimulating factor to promote hematopoietic stem cell mobilization. In addition, some potential mobilization targets, such as prostaglandin E2 receptor and sphingosine 1-phosphate, are still in the research stage. In addition to inherent patient characteristics and treatment options, incorporating biomarkers into the factors affecting mobilization and developing new predictive models will help to effectively predict the failure of hematopoietic stem cell mobilization and improve stem cell mobilization technology.

Erythropoietin/erythropoietin receptor signaling pathway not only participates in bone marrow hematopoiesis, but also regulates the metabolic response of non-hematopoietic tissues, such as brain, heart, skeletal muscle, and adipose tissue. Simultaneously, it can accelerate the mineralization process of periodontal ligament stem cells and reduce oxidative stress damage. However, the mechanism of action on osteogenic differentiation of periodontal ligament stem cells is still unclear.

To investigate the effect and action mechanism of erythropoietin/erythropoietin receptor signaling pathway on osteogenic differentiation of periodontal ligament stem cells.

Enzyme digestion method was used to isolate and culture periodontal ligament stem cells from periodontal disease patients and healthy people. The mRNA and protein levels of erythropoietin receptor in two kinds of periodontal ligament stem cells were detected by qRT-PCR and western blot assay. Erythropoietin receptor expression was silenced by small interfering RNA (siRNA) or activated by erythropoietin. qRT-PCR and western blot assay were used to detect the expression of erythropoietin receptor, levels of osteogenic marker genes Runt-related transcription factor 2 (Runx2), osteocalcin, osteopontin, and bone sialoprotein. Alkaline phosphatase staining and alizarin red staining were applied to measure osteogenic differentiation ability of periodontal ligament stem cells. The phosphorylation of signal transducer and activator of transcription 5 (STAT5) was detected by western blot assay.

(1) The results of qRT-PCR and western blot assay showed that the mRNA and protein levels of erythropoietin receptor in periodontal ligament stem cells in the disease group were significantly lower than those in periodontal ligament stem cells in the healthy group. (2) Alkaline phosphatase staining and alizarin red staining showed that knocking down the erythropoietin receptor can inhibit the osteogenic differentiation ability of periodontal ligament stem cells. qRT-PCR results showed that compared with the control group, knockdown of the erythropoietin receptor group significantly reduced expression levels of Runt-related transcription factor 2, osteocalcin, osteopontin, and bone sialoprotein (P < 0.05). (3) qRT-PCR results showed that after erythropoietin treatment, the expression of erythropoietin receptor in periodontal ligament stem cells recovered. Silencing erythropoietin receptor and then administration of erythropoietin treatment reversed the expression level of erythropoietin receptor. Erythropoietin treatment increased the osteogenic differentiation ability of periodontal ligament stem cells in the disease group and the expression level of the osteogenic marker gene Runt-related transcription factor 2 (P < 0.05). Silencing the expression of STAT5 inhibited this effect of erythropoietin. (4) Western blot assay results showed that with the extension of erythropoietin treatment time, the phosphorylation level of STAT5 increased in periodontal ligament stem cells in the disease group (P < 0.05). The above results indicate that erythropoietin restores the osteogenic differentiation ability of pathological periodontal ligament stem cells by inducing the phosphorylation of STAT5.