Deferoxamine Promotes Peripheral Nerve Regeneration by Enhancing Schwann Cell Function and Promoting Axon Regeneration of Dorsal Root Ganglion.

Deferoxamine (DFO) is a potent iron chelator for clinical treatment of various diseases. Recent studies have also shown its potential to promote vascular regeneration during peripheral nerve regeneration. However, the effect of DFO on the Schwann cell function and axon regeneration remains unclear. In this study, we investigated the effects of different concentrations of DFO on Schwann cell viability, proliferation, migration, expression of key functional genes, and axon regeneration of dorsal root ganglia (DRG) through a series of in vitro experiments. We found that DFO improves Schwann cell viability, proliferation, and migration in the early stages, with an optimal concentration of 25 µM. DFO also upregulates the expression of myelin-related genes and nerve growth-promoting factors in Schwann cells, while inhibiting the expression of Schwann cell dedifferentiation genes. Moreover, the appropriate concentration of DFO promotes axon regeneration in DRG. Our findings demonstrate that DFO, with suitable concentration and duration of action, can positively affect multiple stages of peripheral nerve regeneration, thereby improving the effectiveness of nerve injury repair. This study also enriches the theory of DFO promoting peripheral nerve regeneration and provides a basis for the design of sustained-release DFO nerve grafts.

Enhancing electrocatalytic methanol oxidation of Pd-Ir nanoalloy through electron-rich catalytic interface induced by incorporating phosphorus.

Incorporating less expensive nonmetal phosphorus (P) into noble metal-based catalysts has become a developing strategy to enhance the catalytic performance of electrocatalysts for methanol electrooxidation reaction (MOR), attributing to the electronic and synergistic structure alteration mechanism. In the work, three-dimensional nitrogen-doped graphene anchoring ternary Pd-Ir-P nanoalloy catalyst (Pd7IrPx/NG) was prepared by co-reduction strategy. As a multi-electron system, elemental P adjusts the outer electron structure of Pd and diminishes the particle size of nanocomposites, which heightens the electrocatalytic activity effectively and accelerate MOR kinetics in alkaline medium. The study reveals that the electron effect and ligand effect induced by P atoms on the hydrophilic and electron-rich surface of Pd7Ir/NG and Pd7IrPx/NG samples can reduce the initial oxidation potential and peak potential of COads, showing significantly enhanced the anti-poisoning ability compared with commercial Pd/C as the benchmark. Meanwhile, the stability of Pd7IrPx/NG is significantly higher than that of commercial Pd/C. The facile synthetic approach provides an economic option and a new vision for the development of electrocatalysts in MOR.

Combining surface chemical functionalization with introducing reactive oxygen species boosts ethanol electrooxidation.

The introduction of functional groups or oxygen vacancies into Pd-based electrocatalysts is a powerful strategy for enhancing the electrocatalytic performances for many electrocatalytic reactions. Herein, an amorphous ceria-modified Pd nanocomposite anchored on D-4-amino-phenylalanine (DAP)-functionalized graphene nanosheets (Pd-CeO2-x/FGS) was prepared by a facile and effective one-pot synthetic strategy and further used as an electrocatalyst for the ethanol oxidation reaction (EOR) in alkaline electrolytes. The obtained Pd-CeO2-x/FGS exhibits relatively high electrocatalytic activity, fast kinetics and excellent antipoisoning ability as well as robust durability for EOR, outperforming the comparable electrocatalysts as well as commercial Pd/C. The experimental results show that the enhanced EOR properties of Pd-CeO2-x/FGS can be attributed to the DAP-functionalization and CeO2-x-modification. Adequate functional groups (amino and carboxyl groups) and abundant oxygen vacancies were introduced in Pd-CeO2-x/FGS by DAP-functionalization and CeO2-x-modification. The functional groups facilitate the anchoring of small nanoparticles onto the substrate as well as modulate the electron density of Pd. The oxygen vacancies boost the adsorption ability of the reactive oxygen species (OHads) and accelerate the kinetics of the potential-limiting step for EOR. This study proposes a new strategy for the rational design of highly efficient catalysts for the electro-oxidation reaction.

Functional tissue-engineered microtissue formed by self-aggregation of cells for peripheral nerve regeneration.

BACKGROUND: Peripheral nerve injury (PNI) is one of the essential causes of physical disability with a high incidence rate. The traditional tissue engineering strategy, Top-Down strategy, has some limitations. A new tissue-engineered strategy, Bottom-Up strategy (tissue-engineered microtissue strategy), has emerged and made significant research progress in recent years. However, to the best of our knowledge, microtissues are rarely used in neural tissue engineering; thus, we intended to use microtissues to repair PNI. METHODS: We used a low-adhesion cell culture plate to construct adipose-derived mesenchymal stem cells (ASCs) into microtissues in vitro, explored the physicochemical properties and microtissues components, compared the expression of cytokines related to nerve regeneration between microtissues and the same amount of two-dimension (2D)-cultured cells, co-cultured directly microtissues with dorsal root ganglion (DRG) or Schwann cells (SCs) to observe the interaction between them using immunocytochemistry, quantitative reverse transcription polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA). We used grafts constructed by microtissues and polycaprolactone (PCL) nerve conduit to repair sciatic nerve defects in rats. RESULTS: The present study results indicated that compared with the same number of 2D-cultured cells, microtissue could secrete more nerve regeneration related cytokines to promote SCs proliferation and axons growth. Moreover, in the direct co-culture system of microtissue and DRG or SCs, axons of DRG grown in the direction of microtissue, and there seems to be a cytoplasmic exchange between SCs and ASCs around microtissue. Furthermore, microtissues could repair sciatic nerve defects in rat models more effectively than traditional 2D-cultured ASCs. CONCLUSION: Tissue-engineered microtissue is an effective strategy for stem cell culture and therapy in nerve tissue engineering.

Mxene coupled over nitrogen-doped graphene anchoring palladium nanocrystals as an advanced electrocatalyst for the ethanol electrooxidation.

Development of good support materials is widely adopted as a valid strategy to fabricate high performance electrocatalysts for the ethanol oxidation reaction (EOR). In this study, the small diameter Ti3C2Tx MXene thin nanosheets inserted into three-dimensional nitrogen-doped grapheme (NG) was constructed via a facile hydrothermal method and employed as support materials for anchoring Pd nanocrystals (Pd/Ti3C2Tx@NG). The obtained-Pd/Ti3C2Tx@NG as EOR electrocatalyst in alkaline media outperforms the commercial Pd/C with better electrocatalytic activity, enhanced long-term stability and high CO tolerance. The Ti3C2Tx inserted into NG probably plays a key role for enhancing the properties of the synthesized-catalyst. Inserting Ti3C2Tx into NG allows the electrocatalysts to have high porosity, surface hydrophilicity, sufficient number of anchor sites for Pd nanocrystals and modifies its electronic properties, which can promote the electrocatalytic activity and durability. The enhanced EOR performance endows Pd/Ti3C2Tx@NG with great application potential in fuel cells as an anode catalyst. Furthermore, the prepared Ti3C2Tx@NG is also suitable in various desired applications, especially other oxidation reactions.

Platelet-Rich Plasma Therapy in the Treatment of Diseases Associated with Orthopedic Injuries.

Platelet-rich plasma (PRP) is an autologous platelet concentrate prepared from the whole blood that is activated to release growth factors (GFs) and cytokines and has been shown to have the potential capacity to reduce inflammation and improve tissue anabolism for regeneration. The use of PRP provides a potential for repair due to its abundant GFs and cytokines, which are key in initiating and modulating regenerative microenvironments for soft and hard tissues. Among outpatients, orthopedic injuries are common and include bone defects, ligament injury, enthesopathy, musculoskeletal injury, peripheral nerve injury, chronic nonhealing wounds, articular cartilage lesions, and osteoarthritis, which are caused by trauma, sport-related or other types of trauma, or tumor resection. Surgical intervention is often required to treat these injuries. However, for numerous reasons regarding limited regeneration capacity and insufficient blood supply of the defect region, these treatments commonly result in unsatisfactory outcomes, and follow-up treatment is challenging. The aim of the present review is to explore future research in the field of PRP therapy in the treatment of diseases associated with orthopedic injuries. Impact statement In recent years, platelet-rich plasma (PRP) has become widely used in the treatment of diseases associated with orthopedic injuries, and the results of numerous studies are encouraging. Due to diseases associated with orthopedic injuries being common in clinics, as a conservative treatment, more and more doctors and patients are more likely to accept PRP. Importantly, PRP is a biological product of autologous blood that is obtained by a centrifugation procedure to enrich platelets from whole blood, resulting in few complications, such as negligible immunogenicity from an autologous source, and it is also simple to produce through an efficient and cost-effective method in a sterile environment. However, the applicability, advantages, and disadvantages of PRP therapy have not yet been fully elucidated. The aim of the present review is to explore future research in the field of PRP therapy in the treatment of diseases associated with orthopedic injuries, as well as to provide references for clinics.

Propofol can suppress renal ischemia-reperfusion injury through the activation of PI3K/AKT/mTOR signal pathway.

INTRODUCTION: Renal ischemia/reperfusion injury (IRI) remains one of the most diseases in clinic. The purpose of this study was to investigate the potential role and mechanism of propofol in protecting mice kidney from IRI. METHODS: Renal I/R model was established in C57/BL6 mice by clamping bilateral renal pedicles for 35 min. The mice were randomly divided into four groups: sham group, IR group, IR + Propofol group, and IR + Propofol+LY294002 group. Histological assessment of kidney was conducted by HE staining and the levels of serum creatinine (SCr) and blood urea nitrogen (BUN) of each group were measured. Expressions of inflammatory factors (IL-6, TNF-α) were detected by qRT-PCR and immunoblotting. The expression levels of cleaved Caspasse-3, PI3K, Akt, p-Akt, mTOR, and p-mTOR within renal tissue samples were measured by Western Blot. RESULTS: The levels BUN, Cr and morphological damage score increased significantly after renal IRI. However, such changes could be prevented by propofol. Besides, IRI reduced renal expressions of PI3K, p-Akt, p-mTOR, and increased the levels of IL-6, TNF-α，cl-caspase-3 in kidney, After propofol treatment, these changes were significantly alleviated, but the use of PI3K inhibitor LY294002 could reverse the effects of propofol. CONCLUSION: Propofol can protect renal IRI partially by reducing apoptosis and release of inflammatory cytokines, which is possibly involved in the modulation of the PI3K/AKT/mTOR signaling pathway. Our data suggested that propofol may play certain positive roles in protecting the kidney from IRI.