A TA/Cu2+ Nanoparticle Enhanced Carboxymethyl Chitosan-Based Hydrogel Dressing with Antioxidant Properties and Promoting Wound Healing.

Background: As the first line of immune defense and the largest organ of body, skin is vulnerable to damage caused by surgery, burns, collisions and other factors. Wound healing in the skin is a long and complex physiological process that is influenced by a number of different factors. Proper wound care can greatly improve the speed of wound healing and reduce the generation of scars. However, traditional wound dressings (bandages, gauze, etc.) often used in clinical practice have a single function, lack of active ingredients and are limited in use. Hydrogels with three-dimensional network structure are a potential biomedical material because of their physical and chemical environment similar to extracellular matrix. In particular, hydrogel dressings with low price, good biocompatibility, degradability, antibacterial and angiogenic activity are favored by the public. Methods: Here, a carboxymethyl chitosan-based hydrogel dressing (CMCS-TA/Cu2+) reinforced by copper ion crosslinked tannic acid (TA/Cu2+) nanoparticles was developed. This study investigated the physical and chemical characteristics, cytotoxicity, and angiogenesis of TA/Cu2+ nanoparticles and CMCS-TA/Cu2+ hydrogels. Furthermore, a full-thickness skin defect wound model was employed to assess the in vivo wound healing capacity of hydrogel dressings. Results: The introduction of TA/Cu2+ nanoparticles not only could increase the mechanical properties of the hydrogel but also continuously releases copper ions to promote cell migration (the cell migration could reach 92% at 48 h) and tubule formation, remove free radicals and promote wound healing (repair rate could reach 90% at 9 days). Conclusion: Experiments have proved that CMCS-TA/Cu2+ hydrogel has good cytocompatibility, antioxidant and wound healing ability, providing an advantageous solution for skin repair.

Calcineurin suppresses rat H9c2 cardiomyocyteprotective autophagy under chronic intermittent hypoxia by downregulating the AMPK pathway.

Calcineurin plays a key role in cardiovascular pathogenesis by exerting pro-apoptotic effects in cardiomyocytes. However, whether calcineurin can regulate cardiomyocyte autophagy under conditions of chronic intermittent hypoxia (CIH) remains unclear. Here, we showed that CIH induced calcineurin activity in H9c2 cells, which attenuated adenosine monophosphate-activated protein kinase (AMPK) signaling and inhibited autophagy. In H9c2 cells, autophagy levels, LC3 expression, and AMPK phosphorylation were significantly elevated under conditions of CIH within 3 days. However, after 5 days of CIH, these effects were reversed and calcineurin activity and apoptosis were significantly increased. The calcineurin inhibitor 17-Allyl-1,14-dihydroxy-12-[2-(4-hydroxy-3-methoxycyclohexyl) -1-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo- [22.3.1.04,9]octacos-18- ene-2,3,10,16-tetrone (FK506) restored AMPK activation and LC3 expression and attenuated CIH-induced H9c2 cell apoptosis. In contrast, calcineurin overexpression significantly attenuated the increase in LC3 expression and enhanced H9c2 cell apoptosis under conditions of CIH. Calcineurin inhibition failed to induce autophagy or alleviate apoptosis in H9c2 cells expressing a kinase-dead K45R AMPK mutant. Autophagy inhibition abrogated the protective effects of FK506-mediated calcineurin inhibition. These results indicate that calcineurin suppresses adaptive autophagy during CIH by downregulating AMPK activation. Our findings reveal the underlying mechanism of calcineurin and autophagy regulation during H9c2 cell survival under conditions of CIH and may provide a new strategy for preventing CIH-induced cardiomyocyte damage.

Discovery of BRAF/HDAC Dual Inhibitors Suppressing Proliferation of Human Colorectal Cancer Cells.

The combination of histone deacetylase inhibitor and BRAF inhibitor (BRAFi) has been shown to enhance the antineoplastic effect and reduce the progress of BRAFi resistance. In this study, a series of (thiazol-5-yl)pyrimidin-2-yl)amino)-N-hydroxyalkanamide derivatives were designed and synthesized as novel dual inhibitors of BRAF and HDACs using a pharmacophore hybrid strategy. In particular, compound 14b possessed potent activities against BRAF, HDAC1, and HDAC6 enzymes. It potently suppressed the proliferation of HT-29 cells harboring BRAFV600E mutation as well as HCT116 cells with wild-type BRAF. The dual inhibition against BRAF and HDAC downstream proteins was validated in both cells. Collectively, the results support 14b as a promising lead molecule for further development and a useful tool for studying the effects of BRAF/HDAC dual inhibitors.

Discovery of the First Examples of Threonine Tyrosine Kinase PROTAC Degraders.

The first examples of threonine tyrosine kinase (TTK) PROTACs were designed and synthesized. Two of the most potent molecules, 8e and 8j, demonstrated strong TTK degradation in COLO-205 human colorectal cancer cells with DC50 values of 1.7 and 3.1 nM, respectively. Proteasome-mediated degradation by the compounds could last for approximately 8 h after washout. The degraders 8e and 8j demonstrated improved antiproliferative activities comparing with the structurally similar inhibitor counterparts 8q and 8r. Degraders 8e and 8j also demonstrated reasonable PK profiles and exhibited potent target degradation and in vivo anticancer efficacy in a xenograft mouse model of COLO-205 human colorectal cancer cells upon i.p. administration.

Long-term stable, high accuracy, and visual detection platform for In-field analysis of nitrite in food based on colorimetric test paper and deep convolutional neural networks.

Nitrite is one of the most common carcinogens in daily food. Its simple, rapid, inexpensive, and in-field measurement is important for food safety, based on the requirements of the standard from Codex Alimentarius Commission and China. Using polyacrylonitrile (PAN) and thin layer silica gel (SG), p-aminophenylcyclic acid (SA) and naphthalene ethylenediamine hydrochloride (NEH), as carriers and chromogenic agents, respectively, PAN-NSS as nitrite color sensor is proposed. After fixing and protecting of SA and NEH with layer-upon-layer PAN, the validity period of the test paper can be prolonged from 7 days to more than 30 days. The reproducibility of PAN-NSS preparation is ensured by electrospinning. Combined with PAN-NSS, deep convolutional neural network (DCNN) and APP as a visual monitoring platform, which has the functions of rapid sampling, data processing and transmission, intuitive feedback, etc., and provides a fully integrated detection system for field detection.

NDMA reduction mechanism of UDMH by O3/PMS technology.

Carcinogenic N, N-Dimethylnitrosamine (NDMA) has been reported to generate significantly during ozonation of fuel additive unsymmetrical dimethylhydrazine (UDMH), the combined ozone/Peroxy-Monosulfate (O3/PMS) technology was tried for reducing its formation in this study. The influence of PMS dosages, ozone concentrations, pH, Br- and humic acid (HA) on NDMA formation from UDMH were investigated. In addition, the reduction mechanisms were explored by intermediates identification and Gaussian calculation. The results demonstrated that O3/PMS technology was effective on NDMA reduction, reaching an efficiency of 81% with 80 µM PMS. Higher NDMA reduction rates were achieved by O3/PMS with increasing pH within the scope of research (from 5 to 9), achieving a maximum of 69.9% at pH 9. The presence of bromide ion facilitated NDMA generation during ozonation, but the reduction efficiency by O3/PMS slightly improved from 66.3% to 70.6%. The presence of HA reduced NDMA formation in O3/PMS system. The contribution of SO4•- on NDMA reduction accounted for ~64%, which was higher than that of •OH (41.4%); however, its promotion role on conversing UDMH to NDMA was lower than O3. Therefore, the technology could reduce NDMA formation effectively. In addition, the results of Gaussian calculation manifested that the N atom in -NH2 group of UDMH was easily attacked not only by •OH but also by O3, so it is the key path that determines final NDMA formation. This study would provide reference for reducing NDMA formation during ozonation of UDMH-containing water matrixes.

Pyrido[2, 3-d]pyrimidin-7(8H)-ones as new selective orally bioavailable Threonine Tyrosine Kinase (TTK) inhibitors.

A series of pyrido [2, 3-d]pyrimidin-7(8H)-ones were designed and synthesized as new selective orally bioavailable Threonine Tyrosine Kinase (TTK) inhibitors. One of the representative compounds, 5o, exhibited strong binding affinity with a Kd value of 0.15 nM, but was significantly less potent against a panel of 402 wild-type kinases at 100 nM. The compound also potently inhibited the kinase activity of TTK with an IC50 value of 23 nM, induced chromosome missegregation and aneuploidy, and suppressed proliferation of a panel of human cancer cell lines with low µM IC50 values. Compound 5o demonstrated good oral pharmacokinetic properties with a bioavailability value of 45.3% when administered at a dose of 25 mg/kg in rats. Moreover, a combination therapy of 5o with paclitaxel displayed promising in vivo efficacy against the HCT-116 human colon cancer xenograft model in nude mice with a Tumor Growth Inhibition (TGI) value of 78%. Inhibitor 5o may provide a new research tool for further validating therapeutic potential of TTK inhibition.

[Anterolateral femoral flap combined with fascia lata grafting for repair large Achilles tendon and skin defects].

OBJECTIVE: To investigate the effectiveness of anterolateral femoral flap in combination with fascia lata grafting in repair of large Achilles tendon and skin defects. METHODS: The clinical data of 18 patients with large Achilles tendon and skin defects repaired with anterolateral femoral flap in combination with fascia lata grafting between January 2018 and January 2019 were retrospectively reviewed. There were 14 males and 4 females; age ranged from 32 to 57 years (mean, 42.1 years). There were 9 cases of postoperative infection of Achilles tendon rupture, 1 case of traffic accident injury, and 8 cases of combined infection of skin and Achilles tendon defects after heel trauma. The length of Achilles tendon defect was 4-8 cm, with an average of 5.6 cm; the range of the skin defect was 14 cm×3 cm to 20 cm×5 cm. Flap survival was observed, and ankle function recovery was evaluated according to McComis functional assessment criteria, and dorsal extension and plantar flexion mobility of the affected limb were measured at last follow-up and compared with those of the healthy side. RESULTS: Eighteen cases were followed up 8-24 months, with an average of 16.7 months. All the flaps survived after operation, the flaps were soft and elastic, and the incisions healed by first intention. At last follow-up, 15 cases were excellent, 2 cases were good, and 1 case was acceptable according to McComis functional evaluation criteria, with an excellent and good rate of 94.4%. The two-point discrimination of the heel posterior region of the affected foot was 4-7 mm, with an average of 5.32 mm. The heel-raise test was negative. The dorsiflexion range of the affected side was (21.55±1.26)°, which was significantly different from that of the healthy side (25.23±1.45)° ( t=8.128, P=0.000); the plantar flexion of the affected side was (44.17±1.52)°, which was not significantly different from that of the healthy side (46.13±1.31)° ( t=0.444, P=0.660). CONCLUSION: The application of anterolateral femoral flap in combination with fascia lata grafting for the repair of large Achilles tendon and skin defects can achieve good effectiveness.

Anatomical and Clinical Comparison of Small Free Flaps for Repairing Finger Skin Defects.

The reconstruction of finger defects requires improved functional outcomes and acceptable esthetic outcomes, and small free flaps present a good alternative technique for repairing finger skin defects. From January 2006 to December 2018, we investigated the number and diameter of proximal digital artery perforators, medial plantar artery perforators, and peroneal proper plantar digital arteries of the hallux by dissection and then transplanted free digital arterial perforator flaps, free medial plantar flaps, and free peroneal flaps from the hallux to repair small finger skin defects. The number (SD) of perforators from the medial plantar artery was approximately 2.2 (0.5), and these perforators measured 0.53 (0.20) mm in diameter. The diameter (SD) of the first metatarsal dorsal artery was approximately 1.16 (0.30) mm. A total of 25 patients were included in this study. The transplantation times (SD) for free digital arterial perforator flaps, free medial plantar flaps, and free peroneal flaps from the hallux were 3.5 (0.5) hours, 3.2 (0.7) hours, and 2.0 (0.4) hours, respectively. The follow-up period ranged from 8 to 15 months. All flaps survived and were appropriately shaped. The donor site was either covered with a free flap or directly sutured. Among these 3 types of small flaps, the free peroneal flap from the hallux can be recommended for clinical use because of the large diameter of the contributing vessels, the short operative time, the ease of access, and the improved appearance of the donor site.

A new radiation force balance method for measuring diverging piston source power in the frequency range 20-100 kHz: Theory and experimental verification.

The purpose of this work was to present the results of a theoretical and experimental study in which a new acoustic output power measurement method was developed for a strongly diverged ultrasonic beam (ka < 3, where k is the circular wave number and a is the radius of transducer) using acoustic radiation force. To the best of our knowledge, there is no acceptable and effective method to measure acoustic power P for diverging piston transducers from 20 kHz to 100 kHz in the range ka < 3, it is a unsolved problem acutely. In the study, we used radiation force balance (RFB) method with a novel concave semi-spherical absorbing target in far field to measure the acoustic power up to 54 W. Based on the phase inverse mirror-image model we developed and Bridge's product theorem, the axial radiation force F on the target was first calculated and measured. The maximum difference of the ratio rP/cF (=P/cF) between theoretic and experimental values was smaller than 5%, where c is speed of sound in water. The reproducibility test of acoustic power measurements using two independent methods showed that the measurement uncertainty evaluated less than 10% by the new RFB method was much smaller than that (30%) by the traditional acoustic pressure method in underwater acoustics. It is indicated that the new RFB method is a primary and effective method for acoustic power measurement at least up to 20 W for frequency range 20 kHz to 100 kHz. The similar method was extended to power measurement for the rectangular transducer. Based on this method a new primary method of hydrophone calibration was also developed.

Evaluation of sensory function and recovery after replantation of fingertips at Zone I in children.

Sensory function is the most significant criterion when evaluating the prognosis of replanted fingers. Current clinical research has focused on surgical techniques and indications for finger replantation; however, few studies have focused on recovery of finger sensory function after replantation. This study retrospectively assessed data of eight patients who had undergone nine Zone I replantations of the fingertips in the First Affiliated Hospital of Sun Yat-sen University of China from July 2014 to January 2016. Variations in the extent of damage, with the residual vessels or nerves in some fingers being too short or even missing, prevented tension-free suture repair in some patients. Thus, repair of four of the nine fingertips included arteriovenous anastomosis, the remaining five undergoing arterial anastomosis during replantation of the amputated fingers. Three patients underwent nerve repair, whereas the remaining six cases did not. Fingertip replantations were successful in all eight patients. Compared with the patients without vascular anastomosis, no obvious atrophy was visible in the fingertips of patients who did undergo vascular anastomosis during replantation and their sensory function did recover. Fingertip replantation provides good sensory function and cosmetic outcomes when good artery and vein anastomoses have been created, even when digital nerves have not been repaired.

[PROMOTION EFFECT OF FTY-720P ON TREATMENT OF BONE DEFECT WITH ALLOGRAFT BONE BY SUPPRESSING OSTEOCLAST FORMATION AND FUNCTION].

OBJECTIVE: To explore whether FTY-720P could enhance the effect of allograft bone for bone defect repair by suppressing osteoclast formation and function. METHODS: Animal experiment: Forty-eight New Zealand white rabbits were selected to establish the tibia defect model (1.5 cm in length) and were divided into 4 groups (n = 12). Defect was not repaired in group A, defect was repaired with allograft bone in group B, with autogenous fibula in group C, and with allograft bone and FTY-720P in group D. Lane-Sandhu scoring system and bone density examination were used to evaluate the effect at 2, 4, 8, and 12 weeks after operation. Cell experiment: Bone marrow-derived mononuclear phagocytes (BMMs) were harvested from 1-month-old Sprague Dawley rats and induced into osteoclasts with macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κ B ligand (RANKL), then were identified with tartrate-resistant acid phosphatas (TRAP). According to different concentrations of FTY-720P before induction, experiment was divided into 0, 500, 600, 700, 800, 900, 1,000, and 1,500 ng/mL groups. The effect of FTY-720P was studied by counting the number of osteoclasts and the number of bone resorption lacunae made by osteoclasts. RESULTS: Animal experiment: Lane-Sandhu score showed no significant difference between groups at 2 weeks after operation (P > 0.05), but the score was significantly better in groups C and D than groups A and B, and in group B than group A (P < 0.05). The bone density of group C was significantly greater than that of groups A, B, and D at 2 weeks after operation (P < 0.05), but no significant difference was found among groups A, B, and D (P > 0.05); the bone density of groups B, C, and D was significantly greater than that of group A at 4, 8, and 12 weeks (P < 0.05), but no significant difference was shown among groups B, C, and D (P > 0.05). Cell experiment: BMMs could be induced into osteoclasts by the addition of M-CSF and RANKL, which could be proved by counting the number of the nuclear and TRAP staining. The osteoclasts were significantly more in 0, 500, 600, 700, 800, 900 ng/mL groups than 1 000 and 1 500 ng/mL groups (P < 0.05), in 0, 500, 600, and 700 ng/mL groups than 800 and 900 ng/mL groups (P < 0.05), in 0, 500, 600 ng/mL groups than 700 ng/mL group (P < 0.05); and there was no significant difference between the other groups (P > 0.05). The number of bone resorption lacunae in 0, 500, 600, and 700 ng/mL groups was significantly higher than that in 800, 900, 1,000, and 1,500 ng/mL groups (P < 0.05), and it was significantly higher in 0, 500 and 600 ng/mL groups than 700 ng/mL group (P < 0.05), but difference was not significant between the other groups (P > 0.05). CONCLUSION: FTY-720P combined with allograft bone for bone defect repair can have the same effect to autogenous bone by means of inhibiting osteoclast formation and function, which reduces bone loss.

FTY-720P Suppresses Osteoclast Formation by Regulating Expression of Interleukin-6 (IL-6), Interleukin-4 (IL-4), and Matrix Metalloproteinase 2 (MMP-2).

BACKGROUND Osteoclast formation is closely related to the immune system. FTY720, a new immunosuppressive agent, has some functions in immune regulation. Its main active ingredients become FTY-720P in vivo by phosphorylation modification. The objective of this study was to determine the effects of FTY-720 with various concentrations on osteoclasts in vitro. MATERIAL AND METHODS RAW264.7 cells and bone marrow-derived mononuclear phagocytes (BMMs) were treated with RANKL to obtain osteoclasts in vitro. To investigate the role of FTY-720 in osteoclast formation, trap enzyme staining was performed and the number of osteoclasts was counted. Bone slices were stained with methylene blue, we counted the number of lacunae after bone slices were placed into dishes together with osteoclasts, and we observed the effect and function of FTY-720 in osteoclasts induced by RAW264.7 cells and BMMs. Then, we used a protein array kit to explore the effects of FTY-720P on osteoclasts. RESULTS The results of enzyme trap staining and F-actin staining experiments show that, with the increasing concentration of FTY-720P, the number of osteoclast induced by RAW264.7 cells and BMMs gradually decreased (P<0.05), especially when the FTY-720P concentration reached 1000 ng/ml, and the number of osteoclasts formed was the lowest (P<0.05). With bone lacuna toluidine blue staining, the results also show that, with the increasing concentration of FTY-720P, the number of bone lacuna gradually decreased (P<0.05), and the number of lacunae is lowest when the concentration reached 800 ng/ml. Finally, protein array results showed that IL-4, IL-6, IL-12, MMP-2, VEGF-C, GFR, basic FGF, MIP-2, and insulin proteins were regulated after FTY-720P treatment. CONCLUSIONS FTY-720P can suppress osteoclast formation and function, and FTY-720P induces a series of cytokine changes.

[BIOMECHANICAL STUDY ON Lisfranc LIGAMENT RECONSTRUCTION WITH AUTOGENOUS TENDON].

OBJECTIVE: To explore the feasibility of Lisfranc ligament reconstruction with autogenous tendon through biomechanical testing. METHODS: Twelve fresh-frozen cadaveric lower limbs were prepared three sequential testing conditions: intact Lisfranc ligament (intact group), disrupted Lisfranc ligament (disrupted group), and Lisfranc ligament reconstruction (reconstruction group). Under fixing on the Bose mechanical test machine, three models were given 0-600 N axial loading in the neutral position and the plantar flexion of 30 degrees according to the speed of 10 N/s, every 100 N load with a 1-minute interval. The medial cuneiform (C1) and the second metatarsal (M2) base displacement and the foot transverse arch height were recorded under different loads. RESULTS: In the neutral position and the plantar flexion of 30 degrees, C1-M2 displacement and foot transverse arch height showed an increasing trend with increased load under 0-600 N axial loading. There were significant differences in C1-M2 displacement variation in 2 positions among groups (P < 0.05). In disrupted group, the C1-M2 displacement variation in neutral position was significantly lower than that in plantar flexion of 30 degrees (t = 7.392, P = 0.000). In the neutral position, the foot transverse arch height variation in the disrupted group and the reconstruction group was significantly higher than that in the intact group (P < 0.05), but there was no significant difference between the disrupted group and reconstruction group (P > 0.05). CONCLUSION: Lisfranc ligament reconstruction with autogenous tendon can reduce the C1-M2 displacement variation and stabilize Lisfranc joint to a certain degree. Reconstruction of both dorsal ligament and Lisfranc ligament will not improve the buffering capacity. The C1-M2 displacement variation in the plantar flexion of 30 degrees is more obvious than that in neutral position, so it is helpful to improve clinical diagnosis of occult Lisfranc damage.

Efficacy of combined therapy of periosteum and bone allograft in a critical-sized defect model in New Zealand white rabbits.

BACKGROUND: Large segmental bone defects caused by trauma, infection, or bone tumor resection are difficult to cure and have been a problem in the field of bone repair for decades. The objective of this study was to discuss the efficacy of combined therapy of free periosteum and bone allograft in treating bone defects and to provide a theoretical basis for clinical application of this therapy. MATERIAL/METHODS: A unilateral tibia cortical defect model in New Zealand white rabbits was established according to Girolamo method. Total 48 rabbits were randomized into 3 groups: a simple bone defect group (n=16), an autogenous bone graft group (n=16), and a periosteum and bone allograft combined therapy group (n=16). The efficacy was evaluated by imaging inspections and scoring, HE staining, and RT-PCR in postoperative weeks 2, 4, 8, and 12. RESULTS: The results of imaging and histopathological inspections in the study indicated that in postoperative weeks 4, 8, and 12 the experimental and control groups had statistically significant differences in Lane-Sandhu radiographic scoring and relative bone density when compared with the simple bone defect group (P<0.05). The RT-PCR results suggested that the expression of SPP-1, BMP-2, and VEGF in the experimental group was higher than in the control group (P<0.05) and the expression of Col Ia1 in the control group was higher than in the experimental group (P<0.05). CONCLUSIONS: Efficacies of the combined therapy (periosteum combined with bone allografting) and the criterion standard therapy (autogenous bone grafting) are equivalent in treating bone defects in New Zealand white rabbits.

An integrated low phase noise radiation-pressure-driven optomechanical oscillator chipset.

High-quality frequency references are the cornerstones in position, navigation and timing applications of both scientific and commercial domains. Optomechanical oscillators, with direct coupling to continuous-wave light and non-material-limited f × Q product, are long regarded as a potential platform for frequency reference in radio-frequency-photonic architectures. However, one major challenge is the compatibility with standard CMOS fabrication processes while maintaining optomechanical high quality performance. Here we demonstrate the monolithic integration of photonic crystal optomechanical oscillators and on-chip high speed Ge detectors based on the silicon CMOS platform. With the generation of both high harmonics (up to 59 th order) and subharmonics (down to 1/4), our chipset provides multiple frequency tones for applications in both frequency multipliers and dividers. The phase noise is measured down to -125 dBc/Hz at 10 kHz offset at ~400 µW dropped-in powers, one of the lowest noise optomechanical oscillators to date and in room-temperature and atmospheric non-vacuum operating conditions. These characteristics enable optomechanical oscillators as a frequency reference platform for radio-frequency-photonic information processing.