A Pump-Free Strategy for the Controllable Generation of Alginate Microgels as Cellular Microcarriers.

Microgels are advanced scaffolds for tissue engineering due to their proper biodegradability, good biocompatibility, and high specific surface area for effective oxygen and nutrient transfer. However, most of the current monodispersed microgel fabrication systems rely heavily on various precision pumps, which highly increase the cost and complexity of their downstream application. In this work, we developed a simple and facile system for the controllable generation of uniform alginate microgels by integrating a gas-shearing strategy into a glass microfluidic device. Importantly, the cell-laden microgels can be rapidly prepared in a pump-free manner under an all-aqueous environment. The three-dimensional cultured green fluorescent protein-human A549 cells in alginate microgels exhibited enhanced stemness and drug resistance compared to those under two-dimensional conditions. The pancreatic cancer organoids in alginate microgels exhibited some of the key features of pancreatic cancer. The proposed microgels showed decent monodispersity, biocompatibility, and versatility, providing great opportunities in various biomedical applications such as microcarrier fabricating, organoid engineering, and high-throughput drug screening.

Advances in Microfluidic Technologies in Organoid Research.

Organoids have emerged as major technological breakthroughs and novel organ models that have revolutionized biomedical research by recapitulating the key structural and functional complexities of their in vivo counterparts. The combination of organoid systems and microfluidic technologies has opened new frontiers in organoid engineering and offers great opportunities to address the current challenges of existing organoid systems and broaden their biomedical applications. In this review, the key features of the existing organoids, including their origins, development, design principles, and limitations, are described. Then the recent progress in integrating organoids into microfluidic systems is highlighted, involving microarrays for high-throughput organoid manipulation, microreactors for organoid hydrogel scaffold fabrication, and microfluidic chips for functional organoid culture. The opportunities in the nascent combination of organoids and microfluidics that lie ahead to accelerate research in organ development, disease studies, drug screening, and regenerative medicine are also discussed. Finally, the challenges and future perspectives in the development of advanced microfluidic platforms and modified technologies for building organoids with higher fidelity and standardization are envisioned.

Recent advances in defined hydrogels in organoid research.

Organoids are in vitro model systems that mimic the complexity of organs with multicellular structures and functions, which provide great potential for biomedical and tissue engineering. However, their current formation heavily relies on using complex animal-derived extracellular matrices (ECM), such as Matrigel. These matrices are often poorly defined in chemical components and exhibit limited tunability and reproducibility. Recently, the biochemical and biophysical properties of defined hydrogels can be precisely tuned, offering broader opportunities to support the development and maturation of organoids. In this review, the fundamental properties of ECM in vivo and critical strategies to design matrices for organoid culture are summarized. Two typically defined hydrogels derived from natural and synthetic polymers for their applicability to improve organoids formation are presented. The representative applications of incorporating organoids into defined hydrogels are highlighted. Finally, some challenges and future perspectives are also discussed in developing defined hydrogels and advanced technologies toward supporting organoid research.

Responses of transcriptome and metabolome in the roots of Pugionium cornutum (L.) Gaertn to exogenously applied phthalic acid.

BACKGROUND: The yield and quality of Pugionium cornutum (L.) Gaertn., a healthy, green vegetable with low sugar and high protein contents and high medicinal value, is severely affected by autotoxicity, which is a leading factor in the formation of plant disease. To help characterize the autotoxicity mechanism of P. cornutum (L.) Gaertn., we performed transcriptomic and metabolic analysis of the roots of P. cornutum (L.) Gaertn. response to phthalic acid, an autotoxin from P. cornutum (L.) Gaertn. RESULTS: In this study, high-throughput sequencing of nine RNA-seq libraries generated from the roots.of P. cornutum (L.) Gaertn. under different phthalic acid treatments yielded 37,737 unigenes. In total, 1085 (703 upregulated and 382 downregulated) and 5998 (4385 upregulated and 1613 downregulated) DEGs were identified under 0.1 and 10 mmol·L- 1 phthalic acid treatment, respectively, compared with the control treatment. Glutathione metabolism was among the top five important enriched pathways. In total, 457 and 435 differentially accumulated metabolites were detected under 0.1 and 10 mmol·L- 1 phthalic acid treatment compared with the control, respectively, of which 223 and 253, respectively, increased in abundance. With the increase in phthalic acid concentration, the accumulation of ten metabolites increased significantly, while that of four metabolites decreased significantly, and phthalic acid, dambonitol, 4-hydroxy-butyric acid, homocitrulline, and ethyl ß-D-glucopyranoside were 100 times more abundant under the 10 mmol·L- 1 phthalic acid treatment than under the control. Seventeen differentially expressed genes significantly associated with phthalic acid content were identified. In addition, the L-histidinol content was highest under 0.1 mmol·L- 1 phthalic acid, and a total of eleven differentially expressed genes were significantly positively correlated with the L-histidinol content, all of which were annotated to heat shock proteins, aquaporins and cysteine proteases. CONCLUSIONS: Accumulation of autotoxins altered the metabolic balance in P. cornutum (L.) Gaertn. and influenced water absorption and carbon and nitrogen metabolism. These important results provide insights into the formation mechanisms of autotoxicity and for the subsequent development of new control measures to improve the production and quality of replanted plants.

Topological Radiated Dendrites Featuring Persistent Bactericidal Activity for Daily Personal Protection.

Many substances in nature show radiated topological structure and possess excellent bio-adhesion ability. Herein, regulating the topological structure of Zn2 GeO4 :Mn persistent phosphors is achieved with a molecular coordination method. The morphology of the Zn2 GeO4 :Mn phosphors is well-tuned from nanorods to radiated dendrites by changing the coordination capability of the surface ligand. Due to the structural matching and multivalent interactions, Zn2 GeO4 :Mn radiated dendrites show strong adhesion affinity toward organisms. Moreover, the porous radiated structure offers Zn2 GeO4 :Mn with a large surface area for photocatalysis. Efficient bacterial adhesion and good long persistent photocatalysis activity are observed in the Zn2 GeO4 :Mn radiated dendrites, which endows Zn2 GeO4 :Mn with persistent antibacterial activity even in the dark. Further, the Zn2 GeO4 :Mn spike flowers loaded fabrics exhibit potent persistent antibacterial properties. Mask and towel fabricated with the antibacterial fabrics can inhibit bacterial growth effectively and no bacteria are observed to pass through the antibacterial mask, suggesting that antibacterial mask can guarantee our health and can be utilized repeatedly. The developed Zn2 GeO4 :Mn dendrites possess ideal ability in long-term bacterial inhibition, making them valuable in the fields of medical protection and food packaging.

Randomized research on the mechanism of local oxygen therapy promoting wound healing of diabetic foot based on RNA-seq technology.

BACKGROUND: High purity oxygen therapy has good clinical efficacy in the treatment of diabetic foot (DF), but its mechanism of promoting wound healing has been unclear. METHODS: Patients with DF were randomly divided into an experimental group and a control group. The experimental group was given local oxygen therapy (LOT) by a micro-oxygen therapy instrument, which administered uninterrupted >95% pure oxygen for 24 h at a flow rate of 3 mL/h. Six skin samples from the experimental group before and after treatment underwent RNA sequencing (RNA-seq), and the differentially expressed genes (DEGs) were screened. RESULTS: The clinical results showed that the mean wound healing time of the experimental group was 26 days (P<0.05); the healing area of the experimental group was 3.1-15.3 cm3 , with a mean of 8.8 cm3 , and that of the control group was 2.4-10.4 cm3 (P<0.05). LOT promoted the healing of DF wounds mainly through the tumor necrosis factor (TNF) signaling pathway and the apoptosis pathway. CONCLUSIONS: According to our results, LOT can promote DF healing mainly by inhibiting the local oxidative stress reaction of wound skin and by inhibiting the inflammatory and apoptotic pathways. The molecular markers and pathways screened warrant further study.

Synthesis and Biomedical Applications of Lanthanides-Doped Persistent Luminescence Phosphors With NIR Emissions.

Persistent luminescence phosphors (PLPs) are largely used in biomedical areas owing to their unique advantages in reducing the autofluorescence and light-scattering interference from tissues. Moreover, PLPs with long-lived luminescence in the near-infrared (NIR) region are able to be applied in deep-tissue bioimaging or therapy due to the reduced light absorption of tissues in NIR region. Because of their abundant election levels and energy transfer channels, lanthanides are widely doped in PLPs for the generation of NIR persistent emissions. In addition, the crystal defects introduced by lanthanides-doping can serves as charge traps in PLPs, which contributes to the enhancement of persistent luminescence intensity and the increase of persistent time. In this paper, the research progress in the synthesis and biomedical applications of lanthanides-doped PLPs with NIR emissions are systematically summarized, which can provide instructions for the design and applications of PLPs in the future.

[Clinical study of local injection of autologous platelet-rich plasma in treatment of diabetic foot ulcer].

OBJECTIVE: To investigate the effectiveness of local injection of autologous platelet-rich plasma (PRP) in treatment of diabetic foot ulcer. METHODS: Between October 2017 and October 2018, 90 diabetic foot ulcer patients who met the selection criteria were randomly divided into 3 groups: PRP injection group (group A, PRP was injected and hydrogel dressing covered the wounds), PRP covered group (group B, PRP gel and hydrogel dressing covered the wounds), and the control group (group C, hydrogel dressing covered the wounds), 30 cases in each group. There was no significant difference in gender, age, injured side, disease duration, preoperative glycosylated hemoglobin, wound size, and Wagner grading between groups (P>0.05). The frequency of treatments and hospitalization day in all groups and the total amount of PRP application in groups A and B were recorded. The wound healing condition was recorded during the treatment, and the wound healing rate was calculated at 3 months after the first debridement. RESULTS: The frequency of treatments in groups A, B, and C were (10.2±0.8), (11.4±0.6), (12.5±0.5) times, respectively. The total amount of PRP application of groups A and B were (306±24) and (342±18) mL, respectively. There was no significant difference in the frequency of treatments and the total amount of PRP application between groups (P>0.05). The hospitalization days of groups A, B, and C were (40.5±1.8), (62.1±2.3), and (88.6±1.4) days, respectively, showing significant differences between groups (P<0.05). In the course of treatment, the necrosis and exudation of the wounds gradually reduced, the areas of wounds gradually reduced; and the above conditions of group A were significantly better than groups B and C, and group B was better than group C. At 3 months after the first debridement, the wound healing rates of groups A, B, and C were 93.2%±0.8%, 52.1%±1.1%, and 21.3%±1.3%, respectively, with significant differences between groups (P<0.05). CONCLUSION: PRP can effectively promote the repair of diabetic foot ulcer. The effectiveness of local injection of PRP is superior to the local coverage.

[Research progress of severed limb preservation by perfusion].

OBJECTIVE: To summarize the research progress of severed limb preservation by perfusion and to analyze difference in effect of severed limb preservation by different perfusate. METHODS: The domestic and foreign related literature about severed limb preservation by perfusion was extensively reviewed and analyzed. RESULTS: Currently the main perfusate includes organ perfusate, free radical scavengers, energy mixture, blood substitutes, and whole blood. They can reduce the skeletal muscle's ischemia-reperfusion injury in different degrees. CONCLUSION: Different perfusate can reduce the skeletal muscle's ischemia-reperfusion injury in different degrees, but the best effect of perfusate and personalized preservation method need further study.

[Effect of different temperatures on system of in vitro physiological environment fostering limbs].

OBJECTIVE: To investigate the effects of different temperatures on the system of in vitro physiological environment fostering limbs. METHODS: Twenty-four limbs were harvested from 6 adult Bama mini pigs and were randomly divided into 4 groups (n=6) according to different temperatures: limbs were placed in in vitro physiological environment fostering limbs at 26 degrees C (group A), 4 degrees C (group B), 10 degrees C (group C), and 18 degrees C (group D). After 12 hours of perfusion, the morphology observation was done for the structure and ultrastructure changes of the skeletal muscle by light microscope and transmission electron microscope. The mRNA levels of tumor necrosis factor n (TNF-alpha) and interleukin 10 (IL-1beta) were detected by real-time fluorescent quantitative PCR (RT-qPCR). RESULTS: Histological results showed that the skeletal muscle exhibited mild edema, integrity of the sarcolemma, and occasional perivascular inflammatory cell infiltration in groups B, C, and D, meanwhile, the cells of group C had normal morphology; however, muscle fibers degenerated, muscle cells were seriously damaged, a great number of inflammatory cells infiltrated in the fractured muscle fibers in group A. Transmission electron microscope results showed as follows: the muscle fibers arranged in disorder, and many focal solubility necrosis occurred in group A; the muscle fibers arranged in order relatively and sarcolemma was still intact, with mild swelling and flocculent degenerative mitochondria in group B; a large number of muscle fibers arranged in order and regularity with clear sarcomere in group C; and the muscle fibers arranged in disorder and irregularity and partly dissolved in group D. RT-qPCR results showed that the expressions of inflammatory factor TNF-alpha and IL-1beta mRNA in group A were significantly higher than those in groups B, C, and D (P < 0.05); the expressions were significantly lower in groups B and C than in group D, and in group C than in group B (P < 0.05). CONCLUSION: In the system of in vitro physiological environment fostering limbs, temperature plays an important role in the preservation of amputated limbs. It is suggested that 10 degrees C can significantly attenuate the reperfusion-induced skeletal muscle cell injuries in this system.