Facile Size Tunable Skin-Adaptive Patch for Accelerating Wound Healing.

Owing to the moist and curved interfaces of skin wounds, enhancing the adhesiveness while maintaining delivery efficacy of biomolecules has drawn significant attention in advanced wound dressings. Despite tremendous trials to load biomolecules with sound adhesiveness, the complicated fabricating processes and abnormal allergic responses that are attributed to chemical moiety-based adhesives remain as major problems. To this end, in this study a one-step fabrication process is developed to manufacture microstructures with both a therapeutic (cylindrical structure for embossed structure human adipose-derived stem cell sheet, ESS) and an adhesive part (octopi-inspired structure of adhesive, OIA), which ESOIA is called. OIA showed the highest adhesion strength in both dry (1.48 N cm-2) and wet pig skin conditions (0.81 N cm-2), maintaining the adhesive properties after repeated attach-detach trials. ESS from the therapeutic part of ESOIA also showed an enhanced angiogenic effect compared with the ones that are normally cultured in vitro. ESS also showed improved in vivo wound healing outcomes following enhanced cell engraftment compared to the cell injection group by means of intact cell-extracellular matrix interactions.

Mitochondrial transfer mediates endothelial cell engraftment through mitophagy.

Ischaemic diseases such as critical limb ischaemia and myocardial infarction affect millions of people worldwide1. Transplanting endothelial cells (ECs) is a promising therapy in vascular medicine, but engrafting ECs typically necessitates co-transplanting perivascular supporting cells such as mesenchymal stromal cells (MSCs), which makes clinical implementation complicated2,3. The mechanisms that enable MSCs to facilitate EC engraftment remain elusive. Here we show that, under cellular stress, MSCs transfer mitochondria to ECs through tunnelling nanotubes, and that blocking this transfer impairs EC engraftment. We devised a strategy to artificially transplant mitochondria, transiently enhancing EC bioenergetics and enabling them to form functional vessels in ischaemic tissues without the support of MSCs. Notably, exogenous mitochondria did not integrate into the endogenous EC mitochondrial pool, but triggered mitophagy after internalization. Transplanted mitochondria co-localized with autophagosomes, and ablation of the PINK1-Parkin pathway negated the enhanced engraftment ability of ECs. Our findings reveal a mechanism that underlies the effects of mitochondrial transfer between mesenchymal and endothelial cells, and offer potential for a new approach for vascular cell therapy.

Fibroblast function recovery through rejuvenation effect of nanovesicles extracted from human adipose-derived stem cells irradiated with red light.

Fibroblasts (hDFs) are widely employed for skin regeneration and the treatment of various skin disorders, yet research were rarely investigated about restoration of diminished therapeutic efficacy due to cell senescence. The application of stem cell and stem cell-derived materials, exosomes, were drawn attention for the restoration functionality of fibroblasts, but still have limitation for unintended side effect or low yield. To advance, stem cell-derived nanovesicle (NV) have developed for effective therapeutic reagents with high yield and low risk. In this study, we have developed a method using red light irradiated human adipose-derived stem cells (hADSCs) derived NV (R-NVs) for enhancing the therapeutic efficacy and rejuvenating hDFs. Through red light irradiation, we were able to significantly increase the content of stemness factors and angiogenic biomolecules in R-NVs. Treatment with these R-NVs was found to enhance the migration ability and leading to rejuvenation of old hDFs to levels similar to those of young hDFs. In subsequent in vivo experiments, the treatment of old hDFs with R-NVs demonstrated a superior skin wound healing effect, surpassing that of young hDFs. In summary, this study successfully induced rejuvenation and leading to increased therapeutic efficacy to R-NVs treated old hDFs previously considered as biowaste.

Photopolymerizable Hydrogel for Enhanced Intramyocardial Vascular Progenitor Cell Delivery and Post-Myocardial Infarction Healing.

Cell transplantation success for myocardial infarction (MI) treatment is often hindered by low engraftment due to washout effects during myocardial contraction. A clinically viable biomaterial that enhances cell retention can optimize intramyocardial cell delivery. In this study, a therapeutic cell delivery method is developed for MI treatment utilizing a photocrosslinkable gelatin methacryloyl (GelMA) hydrogel. Human vascular progenitor cells, capable of forming functional vasculatures upon transplantation, are combined with an in situ photopolymerization approach and injected into the infarcted zones of mouse hearts. This strategy substantially improves acute cell retention and promotes long-term post-MI cardiac healing, including stabilized cardiac functions, preserved viable myocardium, and reduced cardiac fibrosis. Additionally, engrafted vascular cells polarize recruited bone marrow-derived neutrophils toward a non-inflammatory phenotype via transforming growth factor beta (TGFß) signaling, fostering a pro-regenerative microenvironment. Neutrophil depletion negates the therapeutic benefits generated by cell delivery in ischemic hearts, highlighting the essential role of non-inflammatory, pro-regenerative neutrophils in cardiac remodeling. In conclusion, this GelMA hydrogel-based intramyocardial vascular cell delivery approach holds promise for enhancing the treatment of acute myocardial infarction.

Various Three-Dimensional Culture Methods and Cell Types for Exosome Production.

Cell-based therapies have been used as promising treatments for several untreatable diseases. However, cell-based therapies have side effects such as tumorigenesis and immune responses. To overcome these side effects, therapeutic effects of exosomes have been researched as replacements for cell-based therapies. In addition, exosomes reduced the risk that can be induced by cell-based therapies. Exosomes contain biomolecules such as proteins, lipids, and nucleic acids that play an essential role in cell-cell and cell-matrix interactions during biological processes. Since the introduction of exosomes, those have been proven perpetually as one of the most effective and therapeutic methods for incurable diseases. Much research has been conducted to enhance the properties of exosomes, including immune regulation, tissue repair, and regeneration. However, yield rate of exosomes is the critical obstacle that should be overcome for practical cell-free therapy. Three-dimensional (3D) culture methods are introduced as a breakthrough to get higher production yields of exosomes. For example, hanging drop and microwell were well known 3D culture methods and easy to use without invasiveness. However, these methods have limitation in mass production of exosomes. Therefore, a scaffold, spinner flask, and fiber bioreactor were introduced for mass production of exosomes isolated from various cell types. Furthermore, exosomes treatments derived from 3D cultured cells showed enhanced cell proliferation, angiogenesis, and immunosuppressive properties. This review provides therapeutic applications of exosomes using 3D culture methods.

Fortifying angiogenic efficacy of conditioned media using phototoxic-free blue light for wound healing.

We used a blue organic light-emitting diode (bOLED) to increase the paracrine factors secreted from human adipose-derived stem cells (hADSCs) for producing conditioned medium (CM). Our results showed that while the bOLED irradiation promotes a mild-dose reactive oxygen generation that enhances the angiogenic paracrine secretion of hADSCs, it does not induce phototoxicity. The bOLED enhances paracrine factors via a cell-signaling mechanism involving hypoxia-inducible factor 1 alpha. This study demonstrated that the CM resulting from bOLED treatment shows improved therapeutic effects on mouse wound-healing models. This method contributes to overcoming the barriers to stem-cell therapies, including the toxicity and low yields from other methods such as nanoparticles, synthetic polymers, and even cell-derived vesicles.

Subaqueous free-standing 3D cell culture system for ultrafast cell compaction, mechano-inductive immune control, and improving therapeutic angiogenesis.

Conventional 3D cell culture methods require a comprehensive complement in labor-intensive and time-consuming processes along with in vivo circumstantial mimicking. Here, we describe a subaqueous free-standing 3D cell culture (FS) device that can induce the omnidirectional environment and generate ultrafast human adipose-derived stem cells (hADSCs) that efficiently aggregate with compaction using acoustic pressure. The cell culture conditions were optimized using the FS device and identified the underlying molecular mechanisms. Unique phenomena in cell aggregation have led to extraordinary cellular behavior that can upregulate cell compaction, mechanosensitive immune control, and therapeutic angiogenesis. Therefore, we designated the resulting cell aggregates as "pressuroid." Notably, external acoustic stimulation produced by the FS device affected the pressuroids. Furthermore, the pressuroids exhibited upregulation in mechanosensitive genes and proteins, PIEZO1/2. CyclinD1 and PCNA, which are strongly associated with cell adhesion and proliferation, were elevated by PIEZO1/2. In addition, we found that pressuroids significantly increase angiogenic paracrine factor secretion, promote cell adhesion molecule expression, and enhance M2 immune modulation of Thp1 cells. Altogether, we have concluded that our pressuroid would suggest a more effective therapy method for future cell therapy than the conventional one.

Silica-Based Advanced Nanoparticles For Treating Ischemic Disease.

Recently, various attempts have been made to apply diverse types of nanoparticles in biotechnology. Silica nanoparticles (SNPs) have been highlighted and studied for their selective accumulation in diseased parts, strong physical and chemical stability, and low cytotoxicity. SNPs, in particular, are very suitable for use in drug delivery and bioimaging, and have been sought as a treatment for ischemic diseases. In addition, mesoporous silica nanoparticles have been confirmed to efficiently deliver various types of drugs owing to their porous structure. Moreover, there have been innovative attempts to treat ischemic diseases using SNPs, which utilize the effects of Si ions on cells to improve cell viability, migration enhancement, and phenotype modulation. Recently, external stimulus-responsive treatments that control the movement of magnetic SNPs using external magnetic fields have been studied. This review addresses several original attempts to treat ischemic diseases using SNPs, including particle synthesis methods, and presents perspectives on future research directions.

Ceria Nanoparticles as Copper Chaperones that Activate SOD1 for Synergistic Antioxidant Therapy to Treat Ischemic Vascular Diseases.

All exogenous nanomaterials undergo rapid biotransformation once injected into the body and fall short of executing the intended purpose. Here, it is reported that copper-deposited ceria nanoparticles (CuCe NPs) exhibit enhanced antioxidant effects over pristine ceria nanoparticles, as the released copper buffers the depletion of glutathione while providing the bioavailable copper as a cofactor for the antioxidant enzyme, superoxide dismutase 1. The upregulated intracellular antioxidants along with the ceria nanoparticles synergistically scavenge reactive oxygen species and promote anti-inflammation and M2 polarization of macrophages by modulating signal transducer and activator of transcription 1 and 6 (STAT1 and STAT6). The therapeutic effect of CuCe NPs is demonstrated in ischemic vascular diseases (i.e., murine models of hindlimb ischemia and myocardial infarction) in which the copper-deposition affords increased perfusion and alleviation in tissue damage. The results provide rationale that metal oxide nanomaterials can be designed in a way to induce the upregulation of specific biological factors for optimal therapeutic performance.

Phototoxicity-free blue light for enhancing therapeutic angiogenic efficacy of stem cells.

Low-level light therapy (LLLT) is a safe and noninvasive technique that has drawn attention as a new therapeutic method to treat various diseases. However, little is known so far about the effect of blue light for LLLT due to the generation of reactive oxygen species (ROS) that can cause cell damage. We introduced a blue organic light-emitting diode (bOLED) as a safe and effective light source that could generate a low amount of heat and luminance compared to conventional light sources (e.g., light-emitting diodes). We compared phototoxicity of bOLED light with different light fluences to human adipose-derived stem cells (hADSC). We further explored molecular mechanisms involved in the therapeutic efficacy of bOLED for enhancing angiogenic properties of hADSC, including intracellular ROS control in hADSCs. Using optimum conditions of bOLED light proposed in this study, photobiomodulation and angiogenic properties of hADSCs were enhanced. These findings might open new methods for using blue light in LLLT. Such methods can be implemented in future treatments for ischemic disease.

Bioengineering for vascularization: Trends and directions of photocrosslinkable gelatin methacrylate hydrogels.

Gelatin methacrylate (GelMA) hydrogels have been widely used in various biomedical applications, especially in tissue engineering and regenerative medicine, for their excellent biocompatibility and biodegradability. GelMA crosslinks to form a hydrogel when exposed to light irradiation in the presence of photoinitiators. The mechanical characteristics of GelMA hydrogels are highly tunable by changing the crosslinking conditions, including the GelMA polymer concentration, degree of methacrylation, light wavelength and intensity, and light exposure time et al. In this regard, GelMA hydrogels can be adjusted to closely resemble the native extracellular matrix (ECM) properties for the specific functions of target tissues. Therefore, this review focuses on the applications of GelMA hydrogels for bioengineering human vascular networks in vitro and in vivo. Since most tissues require vasculature to provide nutrients and oxygen to individual cells, timely vascularization is critical to the success of tissue- and cell-based therapies. Recent research has demonstrated the robust formation of human vascular networks by embedding human vascular endothelial cells and perivascular mesenchymal cells in GelMA hydrogels. Vascular cell-laden GelMA hydrogels can be microfabricated using different methodologies and integrated with microfluidic devices to generate a vasculature-on-a-chip system for disease modeling or drug screening. Bioengineered vascular networks can also serve as build-in vasculature to ensure the adequate oxygenation of thick tissue-engineered constructs. Meanwhile, several reports used GelMA hydrogels as implantable materials to deliver therapeutic cells aiming to rebuild the vasculature in ischemic wounds for repairing tissue injuries. Here, we intend to reveal present work trends and provide new insights into the development of clinically relevant applications based on vascularized GelMA hydrogels.

Silica-Capped and Gold-Decorated Silica Nanoparticles for Enhancing Effect of Gold Nanoparticle-Based Photothermal Therapy.

BACKGROUND: Various methods based on gold nanoparticles (AuNPs) have been applied to enhance the photothermal effect. Among these methods, combining gold nanoparticles and stem cells has been suggested as a new technique for elevating the efficiency of photothermal therapy (PT) in terms of enhancing tumor targeting effect. However, to elicit the efficiency of PT using gold nanoparticles and stem cells, delivering large amounts of AuNPs into stem cells without loss should be considered. METHODS: AuNPs, AuNPs-decorated silica nanoparticles, and silica-capped and AuNPs-decorated silica nanoparticles (SGSs) were synthesized and used to treat human mesenchymal stem cells (hMSCs). After evaluating physical properties of each nanoparticle, the concentration of each nanoparticle was estimated based on its cytotoxicity to hMSCs. The amount of AuNPs loss from each nanoparticle by exogenous physical stress was evaluated after exposing particles to a gentle shaking. After these experiments, in vitro and in vivo photothermal effects were then evaluated. RESULTS: SGS showed no cytotoxicity when it was used to treat hMSCs at concentration up to 20 µg/mL. After intravenous injection to tumor-bearing mice, SGS-laden hMSCs group showed significantly higher heat generation than other groups following laser irradiation. Furthermore, in vivo photothermal effect in the hMSC-SGS group was significantly enhanced than those in other groups in terms of tumor volume decrement and histological outcome. CONCLUSION: Our results suggest that additional silica layer in SGSs could protect AuNPs from physical stress induced AuNPs loss. The strategy applied in SGS may offer a prospective method to improve PT.

Development of a stem cell spheroid-laden patch with high retention at skin wound site.

Mesenchymal stem cells such as human adipose tissue-derived stem cells (hADSCs) have been used as a representative therapeutic agent for tissue regeneration because of their high proliferation and paracrine factor-secreting abilities. However, certain points regarding conventional ADSC delivery systems, such as low cell density, secreted cytokine levels, and cell viability, still need to be addressed for treating severe wounds. In this study, we developed a three-dimensional (3D) cavity-structured stem cell-laden system for overdense delivery of cells into severe wound sites. Our system includes a hydrophobic surface and cavities that can enhance the efficiency of cell delivery to the wound site. In particular, the cavities in the system facilitate hADSC spheroid formation, increasing therapeutic growth factor expression compared with 2D cultured cells. Our hADSC spheroid-loaded patch exhibited remarkably improved cell localization at the wound site and dramatic therapeutic efficacy compared to the conventional cell injection method. Taken together, the hADSC spheroid delivery system focused on cell delivery, and stem cell homing effect at the wound site showed a significantly enhanced wound healing effect. By overcoming the limitations of conventional cell delivery methods, our overdense cell delivery system can contribute to biomedical and clinical applications.

Effect of polystyrene nanoplastics and their degraded forms on stem cell fate.

Several studies have examined the effects of micro- and nanoplastics on microbes, cells, and the environment. However, only a few studies have examined their effects-especially, those of their reduced cohesiveness-on cell viability and physiology. We synthesized surfactant-free amine-functionalized polystyrene (PS) nanoparticles (NPs) and PS-NPs with decreased crosslinking density (DPS-NPs) without changing other factors, such as size, shape, and zeta potential and examined their effects on cell viability and physiology. PS- and DPS-NPs exhibited reactive oxygen species (ROS) scavenging activity by upregulating GPX3 expression and downregulating HSP70 (ROS-related gene) and XBP1 (endoplasmic reticulum stress-related gene) expression in human bone marrow-derived mesenchymal stem cells (hBM-MSCs). Additionally, they led to upregulation of MFN2 (mitochondrial fusion related gene) expression and downregulation of FIS1 (mitochondrial fission related gene) expression, indicating enhanced mitochondrial fusion in hBM-MSCs. Cell-cycle analysis revealed that PS- and DPS-NPs increased the proportion of cells in the S phase, indicating that they promoted cell proliferation and, specifically, the adipogenic differentiation of hBM-MSCs. However, the cytotoxicity of DPS-NPs against hBM-MSCs was higher than that of PS-NPs after long-term treatment under adipogenic conditions.

Area light source-triggered latent angiogenic molecular mechanisms intensify therapeutic efficacy of adult stem cells.

Light-based therapy such as photobiomodulation (PBM) reportedly produces beneficial physiological effects in cells and tissues. However, most reports have focused on the immediate and instant effects of light. Considering the physiological effects of natural light exposure in living organisms, the latent reaction period after irradiation should be deliberated. In contrast to previous reports, we examined the latent reaction period after light exposure with optimized irradiating parameters and validated novel therapeutic molecular mechanisms for the first time. we demonstrated an organic light-emitting diode (OLED)-based PBM (OPBM) strategy that enhances the angiogenic efficacy of human adipose-derived stem cells (hADSCs) via direct irradiation with red OLEDs of optimized wavelength, voltage, current, luminance, and duration, and investigated the underlying molecular mechanisms. Our results revealed that the angiogenic paracrine effect, viability, and adhesion of hADSCs were significantly intensified by our OPBM strategy. Following OPBM treatment, significant changes were observed in HIF-1α expression, intracellular reactive oxygen species levels, activation of the receptor tyrosine kinase, and glycolytic pathways in hADSCs. In addition, transplantation of OLED-irradiated hADSCs resulted in significantly enhanced limb salvage ratio in a mouse model of hindlimb ischemia. Our OPBM might serve as a new paradigm for stem cell culture systems to develop cell-based therapies in the future.

Anti-senescence ion-delivering nanocarrier for recovering therapeutic properties of long-term-cultured human adipose-derived stem cells.

BACKGROUND: Human adipose-derived stem cells (hADSCs) have been used in various fields of tissue engineering because of their promising therapeutic efficacy. However, the stemness of hADSCs cannot be maintained for long durations, and their therapeutic cellular functions, such as paracrine factor secretion decrease during long-term cell culture. To facilitate the use of long-term-cultured hADSCs (L-ADSCs), we designed a novel therapeutic anti-senescence ion-delivering nanocarrier (AIN) that is capable of recovering the therapeutic properties of L-ADSCs. In the present study, we introduced a low-pH-responsive ion nanocarrier capable of delivering transition metal ions that can enhance angiogenic paracrine factor secretion from L-ADSCs. The AINs were delivered to L-ADSCs in an intracellular manner through endocytosis. RESULTS: Low pH conditions within the endosomes induced the release of transition metal ions (Fe) into the L-ADSCs that in turn caused a mild elevation in the levels of reactive oxygen species (ROS). This mild elevation in ROS levels induced a downregulation of senescence-related gene expression and an upregulation of stemness-related gene expression. The angiogenic paracrine factor secretion from L-ADSCs was significantly enhanced, and this was evidenced by the observed therapeutic efficacy in response to treatment of a wound-closing mouse model with conditioned medium obtained from AIN-treated L-ADSCs that was similar to that observed in response to treatment with short-term-cultured adipose-derived stem cells. CONCLUSIONS: This study suggests a novel method and strategy for cell-based tissue regeneration that can overcome the limitations of the low stemness and therapeutic efficacy of stem cells that occurs during long-term cell culture.

Delivery of a spheroids-incorporated human dermal fibroblast sheet increases angiogenesis and M2 polarization for wound healing.

Low cell engraftment is a major problem in tissue engineering. Although various methods related with cell sheets have been attempted to resolve the issue, low cell viability due to oxygen and nutrient depletion remains an obstacle toward advanced therapeutic applications. Cell therapy using fibroblasts is thought of as a good alternative due to the short doubling times of fibroblasts together with their immunomodulatory properties. Furthermore, three-dimensional (3D) fibroblasts exhibit unique angiogenic and inflammation-manipulating properties that are not present in two-dimensional (2D) forms. However, the therapeutic effect of 3D fibroblasts in tissue regeneration has not been fully elucidated. Macrophage polarization has been widely studied, as it stimulates the transition from the inflammation to the proliferation phase of wound healing. Although numerous strategies have been developed to achieve better polarization of macrophages, the low efficacy of these strategies and safety issues remain problematic. To this end, we introduced a biocompatible flat patch with specifically designed holes that form a spheroids-incorporated human dermal fibroblast sheet (SIS) to mediate the activity of inflammatory cytokines for M2 polarization and increase angiogenic efficacy. We further confirmed in vivo enhancement of wound healing with an SIS-laden skin patch (SISS) compared to conventional cell therapy.

Dual Ion Releasing Nanoparticles for Modulating Osteogenic Cellular Microenvironment of Human Mesenchymal Stem Cells.

In this study we developed a dual therapeutic metal ion-releasing nanoparticle for advanced osteogenic differentiation of stem cells. In order to enhance the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and induce angiogenesis, zinc (Zn) and iron (Fe) were synthesized together into a nanoparticle with a pH-sensitive degradation property. Zn and Fe were loaded within the nanoparticles to promote early osteogenic gene expression and to induce angiogenic paracrine factor secretion for hMSCs. In vitro studies revealed that treating an optimized concentration of our zinc-based iron oxide nanoparticles to hMSCs delivered Zn and Fe ion in a controlled release manner and supported osteogenic gene expression (RUNX2 and alkaline phosphatase) with improved vascular endothelial growth factor secretion. Simultaneous intracellular release of Zn and Fe ions through the endocytosis of the nanoparticles further modulated the mild reactive oxygen species generation level in hMSCs without cytotoxicity and thus improved the osteogenic capacity of the stem cells. Current results suggest that our dual ion releasing nanoparticles might provide a promising platform for future biomedical applications.

Lightwave-reinforced stem cells with enhanced wound healing efficacy.

Comprehensive research has led to significant preclinical outcomes in modified human adipose-derived mesenchymal stem cells (hADSCs). Photobiomodulation (PBM), a technique to enhance the cellular capacity of stem cells, has attracted considerable attention owing to its effectiveness and safety. Here, we suggest a red organic light-emitting diode (OLED)-based PBM strategy to augment the therapeutic efficacy of hADSCs. In vitro assessments revealed that hADSCs basked in red OLED light exhibited enhanced angiogenesis, cell adhesion, and migration compared to naïve hADSCs. We demonstrated that the enhancement of cellular capacity was due to an increased level of intracellular reactive oxygen species. Furthermore, accelerated healing and regulated inflammatory response was observed in mice transplanted with red light-basked hADSCs. Overall, our findings suggest that OLED-based PBM may be an easily accessible and attractive approach for tissue regeneration that can be applied to various clinical stem cell therapies.

Regulation of intracellular transition metal ion level with a pH-sensitive inorganic nanocluster to improve therapeutic angiogenesis by enriching conditioned medium retrieved from human adipose derived stem cells.

Cell therapy based on human adipose derived stem cells (hADSCs) is a known potential therapeutic approach to induce angiogenesis in ischemic diseases. However, the therapeutic efficacy of direct hADSC injection is limited by a low cell viability and poor cell engraftment after administration. To improve the outcomes of this kind of approach, various types of nanoparticles have been utilized to improve the therapeutic efficacy of hADSC transplantation. Despite their advantages, the adverse effects of nanoparticles, such as genetic damage and potential oncogenesis based on non-degradable property of nanoparticles prohibit the application of nanoparticles toward the clinical applications. Herein, we designed a transition metal based inorganic nanocluster able of pH-selective degradation (ps-TNC), with the aim of enhancing an hADSC based treatment of mouse hindlimb ischemia. Our ps-TNC was designed to undergo degradation at low pH conditions, thus releasing metal ions only after endocytosis, in the endosome. To eliminate the limitations of both conventional hADSC injection and non-degradable property of nanoparticles, we have collected conditioned medium (CM) from the ps-TNC treated hADSCs and administrated it to the ischemic lesions. We found that intracellular increment of transition metal ion upregulated the hypoxia-inducible factor 1α, which can induce vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) expressions. Based on the molecular mechanism, the secretion of VEGF and bFGF by ps-TNC treated hADSCs showed a significant improvement compared to that of untreated cells. Injecting the CM collected from ps-TNC treated hADSCs into the mouse hindlimb ischemia model (ps-TNC-CM group) showed significantly improved angiogenesis in the lesions, with improved limb salvage and decreased muscle degeneration compared to the group injected with CM collected from normal hADSCs (CM group). This study suggests a novel strategy, combining a known angiogenesis molecular mechanism with both an improvement on conventional stem cell therapy and the circumvention of some limitations still present in modern approaches based on nanoparticles.