Differentiated mesenchymal stem cells-derived exosomes immobilized in decellularized sciatic nerve hydrogels for peripheral nerve repair

Peripheral nerve injury (PNI) and the limitations of current treatments often result in incomplete sensory and motor function recovery, which significantly impact the patient's quality of life. While exosomes (Exo) derived from stem cells and Schwann cells have shown promise on promoting PNI repair following systemic administration or intraneural injection, achieving effective local and sustained Exo delivery holds promise to treat local PNI and remains challenging. In this study, we developed Exo-loaded decellularized porcine nerve hydrogels (DNH) for PNI repair. We successfully isolated Exo from differentiated human adipose-derived mesenchymal stem cells (hADMSC) with a Schwann cell-like phenotype (denoted as dExo). These dExo were further combined with polyethylenimine (PEI), and DNH to create polyplex hydrogels (dExo-loaded pDNH). At a PEI content of 0.1%, pDNH showed cytocompatibility for hADMSCs and supported neurite outgrowth of dorsal root ganglions. The sustained release of dExos from dExo-loaded pDNH persisted for at least 21 days both in vitro and in vivo. When applied around injured nerves in a mouse sciatic nerve crush injury model, the dExo-loaded pDNH group significantly improved sensory and motor function recovery and enhanced remyelination compared to dExo and pDNH only groups, highlighting the synergistic regenerative effects. Interestingly, we observed a negative correlation between the number of colony-stimulating factor-1 receptor (CSF-1R) positive cells and the extent of PNI regeneration at the 21-day post-surgery stage. Subsequent in vitro experiments demonstrated the potential involvement of the CSF-1/CSF-1R axis in Schwann cells and macrophage interaction, with dExo effectively downregulating CSF-1/CSF-1R signaling.

Phase II clinical trial of neoadjuvant anti-PD-1 (toripalimab) combined with axitinib in resectable mucosal melanoma

BACKGROUND

The outcome of patients with resectable mucosal melanoma is poor. Toripalimab combined with axitinib has shown impressive results in metastatic mucosal melanoma with an objective response rate of 48.3% and a median progression-free survival of 7.5 months in a phase Ib trial. It was hypothesized that this combination administered in the neoadjuvant setting might induce a pathologic response in resectable mucosal melanoma, so we conducted this trial.

PATIENTS AND METHODS

This single-arm phase II trial enrolled patients with resectable mucosal melanoma. Patients received toripalimab 3 mg/kg once every 2 weeks (Q2W) plus axitinib 5 mg two times a day (b.i.d.) for 8 weeks as neoadjuvant therapy, then surgery and adjuvant toripalimab 3 mg/kg Q2W starting 2 ± 1weeks after surgery for 44 weeks. The primary endpoint was the pathologic response rate according to the International Neoadjuvant Melanoma Consortium recommendations.

RESULTS

Between August 2019 and October 2021, 29 patients were enrolled and received treatment, of whom 24 underwent resection. The median follow-up time was 34.2 months (95% confidence interval 20.4-48.0 months). The pathologic response rate was 33.3% (8/24; 4 pathological complete responses and 4 pathological partial responses). The median event-free survival for all patients was 11.1 months (95% confidence interval 5.3-16.9 months). The median overall survival was not reached. Neoadjuvant therapy was tolerable with 8 (27.5%) grade 3-4 treatment-related adverse events and no treatment-related deaths. Tissue samples of 17 patients at baseline and after surgery were collected (5 responders and 12 nonresponders). Multiplex immunohistochemistry demonstrated a significant increase in CD3+ (P = 0.0032) and CD3+CD8+ (P = 0.0038) tumor-infiltrating lymphocytes after neoadjuvant therapy, particularly in pathological responders.

CONCLUSIONS

Neoadjuvant toripalimab combined with axitinib in resectable mucosal melanoma demonstrated a promising pathologic response rate with significantly increased infiltrating CD3+ and CD3+CD8+ T cells after therapy.

[Clinical characteristics and associated factors of mild cognitive impairment in patients with common cardiovascular diseases]

Objective: To analyze the clinical characteristics of patients with common cardiovascular diseases (CVD, including hypertension, coronary heart disease, atrial fibrillation, and heart failure) combined with mild cognitive impairment (MCI) and explore the potential risk factors of MCI in patients with CVD. Methods: A total of 2 294 patients with common cardiovascular diseases who met the criteria at Cardiology Medical Center in Beijing Anzhen Hospital, Capital Medical University, from June 1, 2021, to January 5, 2022, were retrospectively included. The patients were divided into the normal cognitive function group (1 107 cases) and the MCI group (1 187 cases). Demographic information and CVD status were collected. The information of cognitive function were collected using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) scales. The difference between normal cognitive function and MCI were compared and analyzed. The logistic regression analysis was used to explored risk factors of MCI in CVD patients. Results: A total of 2 294 patients aged (60.6±10.4) years were included, among whom there were 29.99% (688 cases) females. Compared with patients in the normal cognitive function group, patients in the MCI group were older [ (57.9±11.4) vs (63.1±8.9) years old, P<0.001], with a higher proportion of women [26.47% (293 cases) vs 33.28% (395 cases), P<0.001]; there was a higher proportion of patients suffering from hypertension in the MCI group [59.62% (660 cases) vs 64.62% (767 cases), P=0.014］, and more components of CVD [(1.68±0.62) vs (1.74±0.65) components, P=0.017]. The risk factors of MCI in patients with common CVD were increased age, increased depression score, combined with hypertension, and ≥3 common components of CVD, with OR (95%CI) of 1.043 (1.032-1.054), 1.021 (1.004-1.037), 1.151 (1.142-3.439), and 1.137 (1.023-1.797), respectively (all P values <0.05). Increasing education level was observed to be associated with reduced risk of MCI with OR (95%CI) of 0.319 (0.271-0.378) (P<0.05). Conclusions: The incidence of MCI was high in CVD patients. The risk factors of MCI in CVD patients included hypertension and≥3 common components of CVD.

An Innovative Regimen Basing on HFRT/SBRT and RC48-ADC Coactivation for Salvage Therapy in Patients with HER2-Expressing Advanced Solid Tumors

PURPOSE/OBJECTIVE(S)

It is now widely accepted that radiotherapy, especially hypofractionated radiation therapy (HFRT) or stereotactic radiotherapy (SBRT), can modulate tumor phenotypes, enhance antigen presentation and provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). The PRaG therapy is an innovative iRT, when combined with HFRT/SBRT, PD-1/L1 inhibitor and GM-CSF to activate the immune response and modulate the tumor microenvironment to exert the desired in abscopal effect. Previous studies have demonstrated encouraging efficacy of the PRaG regimen in the treatment of advanced refractory tumors. RC48-ADC is a promising anti-HER2 antibody-drug conjugate with inducing immunogenic cell death and widespread release of cancer cell antigens, synergize with immunotherapy by promoting effector T-cell activation. The aim of this study is to explore efficacy and safety of RC48-ADC combined with radiotherapy, PD-1/L1 inhibitor sequential GM-CSF and IL-2(PRaG3.0 regimen) for treatment of HER2-expressing advanced solid tumors.

MATERIALS/METHODS

Participants with advanced, confirmed HER2-expressing (IHC3+, 2+ or 1+) solid tumors that had progressed after standard treatment, or intolerance were enrolled. In a PRaG3.0 regimen cycle, those received RC48-ADC (2.0 mg/kg d1, every 3 weeks), then HFRT (2-3 doses of 5-8 Gy) was delivered for one metastatic lesion every other day, followed by GM-CSF (200 μg d3-7), sequential IL-2(2million IU d8-12), and PD-1/L1 inhibitor was dosing within one week after completion of HFRT. After RC48-ADC combined with PD-1/L1 inhibitor sequential GM-CSF and IL-2 for at least 6 cycles, then maintenance with PD-1/L1 inhibitor was administered until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR). This trial is registered with ClinicalTrials.gov, number NCT05115500.

RESULTS

With the cutoff date of 31 December 2022, a total of 30 patients (n = 6 for gynecological cancer, n = 5 for pancreatic cancer, n = 19 for other cancers) were enrolled, in which 21 patients completed at least 1 tumor assessment. The objective response rate (ORR) was 42.9%, and the disease control rate was 71.4% by RECIST1.1. The ORR was 66.7% in gynecological cancer, 25.3% in pancreatic cancer, and 36.4% in other cancers. Median progression-free survival (PFS) for all patients was 7.0 months (95% CI: 3.4, 10.7). The most common treatment-related adverse events (TRAEs) included fatigue, fever, alopecia and anorexia. Grade ≥3 TRAEs occurred in two patients (6.7%).

CONCLUSION

These preliminary results show that of PRaG3.0 regimen has a manageable safety profile and encouraging antitumor activity in heavily pretreated patients with HER2- expressing cancers. Ultimately the regimen achieved the accurate integration of RT, immunotherapy and targeted therapy.

Impact of PRaG Therapy on Immune Microenvironment of Bilateral Subcutaneous Tumor Model of Colon Cancer

PURPOSE/OBJECTIVE(S)

Immune microenvironment is closely related to the efficacy of PD-1 inhibitors. The immune microenvironment contains a variety of immune cells, including effector T cells (cytotoxic CD8+T cells and effector CD4+T cells), dendritic cells (DC), and Myeloid-derived suppressor cells (MDSCs). The antitumor effects of PRaG therapy have been confirmed in bilateral subcutaneous transplantation tumor model of colon cancer. But the impact of PRaG therapy on immune microenvironment of such model is unclear. Therefore, the study continued to reveal the changes of immune microenvironment in mice.

MATERIALS/METHODS

80 male Balb/c mice aged 6-8 weeks were divided into five groups: control group, PD-1 inhibitor group, radiation group, radiation + PD-1 inhibitor group, and radiation + PD-1 inhibitor +GM-CSF (PRaG therapy) group. Bilateral subcutaneous tumor model of colon cancer in mice was constructed. 3×105 CT26.WT cells were inoculated subcutaneously in the right thigh root, and then the left thigh root 3 days later. Right subcutaneous tumor was selected for radiotherapy of 8 Gy×3. GM-CSF (100ng, i.p.) was given on the 1st day and PD-1 inhibitor (0.25mg/kg, i.p.) was given on the 2nd day after radiotherapy with one cycle every 3 days. On day 15, the spleen, left inguinal lymph node and left subcutaneous tumor of mice were collected. The proportion of immune cells was detected by flow cytometry.

RESULTS

Compared with other groups, PRaG therapy decreased the proportion of cDC1 in left inguinal lymph node, increased the proportion of cDC2 in left subcutaneous tumor and left inguinal lymph node. Moreover, PRaG therapy increased the proportion of CD8+ effector memory T cells and CD226+CD8+T cells in left inguinal lymph nodes. Finally, PRaG therapy increased the proportion of CD4+, CD8+ central memory T cells and CD69+CD8+T cells and reduced the proportion of M-MDSCs in spleen.

CONCLUSION

PRaG therapy can improve the immune microenvironment of spleen, unirradiated tumors and inguinal draining lymph nodes of bilateral subcutaneous tumor model of colon cancer in mice.

Embedded Bioprinting of Breast Tumor Cells and Organoids Using Low-Concentration Collagen-Based Bioinks

Bioinks for 3D bioprinting of tumor models should not only meet printability requirements but also accurately maintain and support phenotypes of tumor surrounding cells to recapitulate key tumor hallmarks. Collagen is a major extracellular matrix protein for solid tumors, but low viscosity of collagen solution has made 3D bioprinted cancer models challenging. This work produces embedded, bioprinted breast cancer cells and tumor organoid models using low-concentration collagen I based bioinks. The biocompatible and physically crosslinked silk fibroin hydrogel is used to generate the support bath for the embedded 3D printing. The composition of the collagen I based bioink is optimized with a thermoresponsive hyaluronic acid-based polymer to maintain the phenotypes of both the noninvasive epithelial and invasive breast cancer cells, as well as cancer-associated fibroblasts. Mouse breast tumor organoids are bioprinted using optimized collagen bioink to mimic in vivo tumor morphology. A vascularized tumor model is also created using a similar strategy, with significantly enhanced vasculature formation under hypoxia. This study shows the great potential of embedded bioprinted breast tumor models utilizing a low-concentration collagen-based bioink for advancing the understanding of tumor cell biology and facilitating drug discovery research.

Radiotherapy for Patients with Locally Advanced Esophageal Squamous Cell Carcinoma Receiving Neoadjuvant Immunotherapy Combined with Chemotherapy

PURPOSE/OBJECTIVE(S)

With the success of immunotherapy in advanced esophageal cancer, neoadjuvant chemo-immunotherapy (CIT) is being increasingly used for local staged esophageal cancer, especially in the context of clinical trials, which brings similar pCR with neoadjuvant chemoradiotherapy and shows promising results. However, there is still a part of potentially operable patients can't undergo surgery after neoadjuvant chemo-immunotherapy. The follow-up treatment and prognosis of this population remain unclear.

MATERIALS/METHODS

Patients pathologically diagnosed with ESCC, clinical stage T1-3N+M0 or T3-4aNanyM0(AJCC 8th), PS 0-1 were retrospectively enrolled from 1/2020 to 6/2021 in Zhejiang Cancer Hospital. All patients firstly received PD-1 inhibitors (Camrelizumab, Sintilimab or Tislelizumab) plus chemotherapy (albumin paclitaxel,260 mg/m²on day 1 plus carboplatin AUC = 5 on day 1) every 3 weeks for 2-4 cycles. For those patients who did not receive surgery, definitive radiotherapy with 50.4Gy/28F or 50Gy/25F was adopted using VMAT, concurrent with chemotherapy or alone. The concurrent chemotherapy regimens included weekly TC (paclitaxel 50 mg/m 2, d1, carboplatin AUC = 2, d1) or S1 (60mg bid d1-14,29-42). The survival outcomes and treatment toxicity were recorded and analyzed.

RESULTS

A total of 56 eligible patients were finally identified from 558 patients who were treated in department of thoracic surgery, 31 patients showed no response to neoadjuvant CIT (6 with PD and 25 with SD), 25 patients achieved PR but did not receive surgery due to poor performance status or refuse to operation. Median age was 66(IQR 56-72) and 55(98.2%) were males. 12(19.6%) were stage II and 44(80.4%) were stage III. Among all the patients,25 (44.6%) received radiotherapy alone, and 31 (55.4%) received chemoradiotherapy after neoadjuvant CIT. The median follow-up was 11.8 months (IQR 8.6-20.1). The median PFS and OS were 16.5 months (95CI 12.9-21.4) and 18.6 months (95CI 11.2-NA), respectively. In the subgroup analysis, the median PFS for patients with PR to CIT was 20.2 moths (95CI:17.23-NA), and 12.9 moths (95CI: 0.68-20.4) for patients with SD or PD, HR was 0.45 (95CI:0.22- 0.93, P = 0.027). No significant difference was observed for patients received radiotherapy alone or chemoradiotherapy with HR = 1.36(95CI:0.69-2.71, P = 0.37). The most common AEs observed during this study were anemia (98.2%), Leukopenia (83.9%), Thrombocytopenia (53.6%). Adverse events of grade≥3 radiation-induced pneumonitis and esophagitis were 12.5% and 32.1%, especially, 6 patients (10.7%) died from esophageal fistula and 2 patients (3.6%) died from grade 5 pneumonitis.

CONCLUSION

For local advanced ESCC patients after neoadjuvant CIT who did not receive surgery, definitive radiotherapy was an optional treatment strategy. However, those patients with no response to CIT also showed poor response to radiotherapy, and particular attention should be paid to treatment related toxicity, especially esophageal fistula.

Regional heterogeneity in short-term associations of meteorological factors, air pollution, and asthma hospitalizations in Guangxi, China

OBJECTIVES

This study aimed to identify and evaluate the short-term and lag effects of environmental factors on asthma hospitalizations in different regions.

STUDY DESIGN

The ecological study on asthma is performed in three regions of Guangxi, China, that are distinctly different in geography and climate.

METHODS

We used distributed lag non-linear models to investigate the exposure-response-lag relationship between meteorological factors, air pollutants, and asthma hospital admissions across the three regions during 2015 (January 1 to December 31).

RESULTS

Cold was an important meteorological factor affecting asthma. At lag 0, the relative risk (RR; 23°C as reference) of cold in the Northwest, Northeast, and South was 1.10 (10°C), 1.14 (8°C), and 1.30 (11°C), respectively. NO2 was identified as the most important air pollutant affecting asthma. The RR of asthma hospitalization increased by 10.9% (at lag 4), 8.1% (at lag 0), and 4.2% (at lag 2) for every 10 μg/m3 increase in NO2 concentration in the Northwest, Northeast, and South, respectively.

CONCLUSIONS

In the three regions of Guangxi, there were differences in the dominant factors affecting asthma hospitalizations. Differences in geography can inform governments as to how to prepare the healthcare system to meet the expected peaks.

A Prospective Clinical Trial of Radiotherapy Combined with PD-1 Inhibitors and GM-CSF, Sequentially Followed by IL-2 (PRaG 2.0) Regimen in Advanced Refractory Solid Tumors

PURPOSE/OBJECTIVE(S)

Radiotherapy could stimulate the immune response and might synergize with PD-1/PD-L1 inhibitors in the clinical treatment of malignancies. Our previous PRaG trial also demonstrated that SBRT/HFRT in combination with PD-1 inhibitors and granulocyte macrophage-colony stimulating factor (GM-CSF) could improve clinical response in patients with advanced refractory solid tumors (ChiCTR1900026175). To further improve the efficacy of immunotherapy combined with radiotherapy, we conducted the PRaG 2.0 trial (ClinicalTrials.gov: NCT04892498) and optimized the PRaG regimen by adding interleukin-2 (IL-2). Preliminary results of PRaG 2.0 had been reported in the 64th ASTRO. Now we report an updated result.

MATERIALS/METHODS

The PRaG 2.0 regimen was administered to patients with advanced refractory solid tumors who lacked or were unable to tolerate standard-of-care treatments. A treatment cycle consisted of SBRT or HFRT (5 or 8 Gy×2-3f) delivered for one metastatic lesion, PD-1 inhibitor dosing within one week after completion of radiotherapy, GM-CSF 200μg subcutaneous (SC) injection once daily for 7 days, and then sequentially followed by IL-2 2million IU SC once daily for 7 days. PRaG 2.0 regimen was repeated every 21 days for at least 2 cycles until no appropriate lesions for irradiation or reached the tolerance dose of normal tissues. Patients who could not continue radiotherapy and had not yet developed progression disease (PD) allowed PD-1 inhibitors to be continued as maintenance therapy until PD or unacceptable toxicity but no more than one year. The primary endpoint was Progression-Free Survival (PFS).

RESULTS

As of 31st October 2022, 51 patients were enrolled in the study, and 42 completed at least one tumor assessment. The median Progression-Free Survival (PFS) was 5.8 months, and the median overall survival (OS) was 13.5 months. The objective response rate (ORR) was 21.4%, and the disease control rate (DCR) was 61.9% according to RECIST version 1.1. Lower plasma levels of Interleukin (IL)-6 and IL-17 at baseline were found to be associated with improved PFS. Treatment-related adverse events (TRAE) occurred in 34 of 42 (78.6%) patients, Grade ≥ 3 TRAEs occurred in 4 patients (9.5%). TRAEs leading to discontinuation of all study treatments occurred in three patients (7.1%).

CONCLUSION

The PRaG 2.0 trial demonstrates that PD-1 inhibitors in combination with SBRT/HFRT, GM-CSF, and IL-2 could be a potential treatment regimen for patients with advanced refractory solid tumors, with an acceptable benefit/risk profile.

Impact of PRaG Therapy on Peripheral Immune Cells of Subcutaneous Tumor Peritoneal Metastasis Model of Colon Cancer

PURPOSE/OBJECTIVE(S)

Immune cells in peripheral blood may be closely related to the efficacy of immune checkpoint inhibitors. T cells originally present in tumors may have limited antitumor effects, and T cells that respond to immune checkpoint inhibitors may be derived from peripheral blood. Therefore, in this study, subcutaneous tumor peritoneal metastasis model of colon cancer was constructed to reveal the changes of T cells and their subsets (CD4+T cells, CD8+T cells, CD226+T cells), MDSCs and their subsets (G-MDSCs, M-MDSCs) in peripheral blood of mice after PRaG therapy.

MATERIALS/METHODS

A total of 90 male Balb/c mice aged 6-8 weeks were divided into five groups: control group, PD-1 inhibitor group, radiation group, radiation + PD-1 inhibitor group, and radiation + PD-1 inhibitor +GM-CSF (PRaG therapy) group. The subcutaneous tumor peritoneal metastasis model of colon cancer was constructed. 3×105 CT26.WT cells was inoculated subcutaneously at the right thigh root, and 5 days later, 1×105 CT26.WT cells was inoculated on the left side at the junction of the anterior superior iliac spine and the midabdominal line. The subcutaneous tumor was selected for radiotherapy of 8 Gy×3. GM-CSF (100ng, i.p.) was given on the 1st day and PD-1 inhibitor (0.25mg/kg, i.p.) was given on the 2nd day after radiotherapy with one cycle every 3 days. On day 22, the peripheral blood of mice was collected. The proportion of immune cells was detected by flow cytometry.

RESULTS

Compared with other groups, PRaG therapy decreased the proportion of CD4+T cells and increased the proportion of CD8+T cells. Moreover, PRaG therapy increased the proportion of CD226+CD4+T cells and CD226+CD8+T cells. Finally, PRaG therapy increased the proportion of M-MDSCs and decreased the proportion of G-MDSCs.

CONCLUSION

PRaG therapy can improve the immune microenvironment of peripheral blood of subcutaneous tumor peritoneal metastasis model of colon cancer in mice.

A Facile Strategy for the Fabrication of Cell-laden Porous Alginate Hydrogels Based on Two-phase Aqueous Emulsions

Porous alginate hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden alginate hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of alginate and caseinate, are crosslinked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the caseinate phase from the ion-crosslinked alginate hydrogel. Those porous alginate hydrogels possess heterogeneous pores around 100 μm and interconnected paths. Human white adipose progenitors (WAPs) encapsulated in these hydrogels self-organize into spheroids and show enhanced viability, proliferation, and adipogenic differentiation, compared to non-porous constructs. As a proof of concept, this porous alginate hydrogel platform is employed to prepare core-shell spheres for coculture of WAPs and colon cancer cells, with WAP clusters distributed around cancer cell aggregates, to investigate cellular crosstalk. This efficacious approach is believed to provide a robust and versatile platform for engineering porous-structured alginate hydrogels for applications as cell carriers and in disease modeling.

[Clinical observation of spontaneous brain activity in children with congenital cortical cataract amblyopia]

Objective: To investigate the characteristics of spontaneous brain activity in children with congenital cortical cataract amblyopia. Methods: A cross-sectional study was conducted. Twenty cases of unilateral congenital cortical cataract amblyopia (unilateral amblyopia group) and 14 cases of bilateral congenital cortical cataract amblyopia (bilateral amblyopia group) were enrolled from January 2022 to December 2022 at the First Affiliated Hospital of Zhengzhou University. Seventeen age and gender matched children with normal visual acuity were recruited as the healthy control group. Resting-state functional MRI (fMRI) was performed on all participants, and the amplitude of low-frequency fluctuations (ALFF) technique was used to analyze their spontaneous brain activities. The original ALFF value of each voxel was divided by the average ALFF value of the whole brain to obtain the standardized ALFF value (referred to as ALFF value), which reflected the intensity of spontaneous brain activity in different brain regions. General demographic data were compared using one-way analysis of variance, Kruskal-Wallis test, and chi-square test. Comparison of ALFF values was conducted using one-way analysis of variance. Results: There were no significant differences in age, gender, distribution of amblyopic eye or non-dominant eye, and degree of refractive error among the three groups (all P>0.05). Compared to the healthy control group, the unilateral amblyopia group showed higher ALFF values in the right posterior lobe of the cerebellum (67 voxels, t=3.48) and left posterior lobe of the cerebellum (71 voxels, t=4.09), and lower ALFF values in the right postcentral gyrus (91 voxels, t=-3.91), right inferior parietal lobule (73 voxels, t=-4.88), right inferior frontal gyrus (78 voxels, t=-4.09), left inferior parietal lobule (556 voxels, t=-4.82), and left inferior frontal gyrus (122 voxels, t=-4.27) (all P<0.01). The bilateral amblyopia group showed higher ALFF values in the right insula (60 voxels, t=3.54), right Rolandic operculum (69 voxels, t=3.73), right posterior lobe of the cerebellum (54 voxels, t=3.43), and left posterior lobe of the cerebellum (143 voxels, t=3.69), and lower ALFF values in the left inferior frontal gyrus (99 voxels, t=-4.39), left postcentral gyrus (231 voxels, t=-4.28), and right inferior parietal lobule (54 voxels, t=-3.77) (all P<0.01). Compared to the unilateral amblyopia group, the bilateral amblyopia group showed higher ALFF values in the left middle frontal gyrus (52 voxels, t=3.15, P=0.029), left posterior lobe of the cerebellum (77 voxels, t=3.39, P=0.001), and right Rolandic operculum (53 voxels, t=3.59, P=0.007). Conclusion: Children with congenital cortical cataract amblyopia exhibit altered spontaneous brain activity in multiple brain regions, and there are differences in spontaneous brain activity changes between unilateral and bilateral amblyopia.

Evaluation of Low-dose Radiation-induced DNA Damage and Repair in 3D Printed Human Cellular Constructs

ABSTRACT

DNA double-strand breaks (DSBs) induced by ionizing radiation (IR) are considered to be the most critical lesion that when unrepaired or misrepaired leads to genomic instability or cell death depending on the radiation exposure dose. The potential health risks associated with exposures of low-dose radiation are of concern since they are being increasingly used in diverse medical and non-medical applications. Here, we have used a novel human tissue-like 3-dimensional bioprint to evaluate low-dose radiation-induced DNA damage response. For the generation of 3-dimensional tissue-like constructs, human hTERT immortalized foreskin fibroblast BJ1 cells were extrusion printed and further enzymatically gelled in a gellan microgel-based support bath. Low-dose radiation-induced DSBs and repair were analyzed in the tissue-like bioprints by indirect immunofluorescence using a well-known DSB surrogate marker, 53BP1, at different post-irradiation times (0.5 h, 6 h, and 24 h) after treatment with various doses of γ rays (50 mGy, 100 mGy, and 200 mGy). The 53BP1 foci showed a dose dependent induction in the tissue bioprints after 30 min of radiation exposure and subsequently declined at 6 h and 24 h in a dose-dependent manner. The residual 53BP1 foci number observed at 24 h post-irradiation time for the γ-ray doses of 50 mGy, 100 mGy, and 200 mGy was not statistically different from mock treated bioprints illustrative of an efficient DNA repair response at these low-dose exposures. Similar results were obtained for yet another DSB surrogate marker, γ-H2AX (phosphorylated form of histone H2A variant) in the human tissue-like constructs. Although we have primarily used foreskin fibroblasts, our bioprinting approach-mimicking a human tissue-like microenvironment-can be extended to different organ-specific cell types for evaluating the radio-response at low-dose and dose-rates of IR.

[The mechanism of S100A7 inducing the migration and invasion in cervical cancer cells]

Objective: To investigate the mechanism of S100A7 inducing the migration and invasion in cervical cancers. Methods: Tissue samples of 5 cases of cervical squamous cell carcinoma and 3 cases of adenocarcinoma were collected from May 2007 to December 2007 in the Department of Gynecology of the Affiliated Hospital of Qingdao University. Immunohistochemistry was performed to evaluate the expression of S100A7 in cervical carcinoma tissues. S100A7-overexpressing HeLa and C33A cells were established with lentiviral systems as the experimental group. Immunofluorescence assay was performed to observe the cell morphology. Transwell assay was taken to detect the effect of S100A7-overexpression on the migration and invasion of cervical cancer cells. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to examine the mRNA expressions of E-cadherin, N-cadherin, vimentin and fibronectin. The expression of extracellular S100A7 in conditioned medium of cervical cancer cell was detected by western blot. Conditioned medium was added into Transwell lower compartment to detect cell motility. Exosomes were isolated and extracted from the culture supernatant of cervical cancer cell, the expressions of S100A7, CD81 and TSG101 were detected by western blot. Transwell assay was taken to detect the effect of exosomes on the migration and invasion of cervical cancer cells. Results: S100A7 expression was positively expressed in cervical squamous carcinoma and negative expression in adenocarcinoma. Stable S100A7-overexpressing HeLa and C33A cells were successfully constructed. C33A cells in the experimental group were spindle shaped while those in the control group tended to be polygonal epithelioid cells. The number of S100A7-overexpressed HeLa cells passing through the Transwell membrane assay was increased significantly in migration and invasion assay (152.00±39.22 vs 105.13±15.75, P<0.05; 115.38±34.57 vs 79.50±13.68, P<0.05). RT-qPCR indicated that the mRNA expressions of E-cadherin in S100A7-overexpressed HeLa and C33A cells decreased (P<0.05) while the mRNA expressions of N-cadherin and fibronectin in HeLa cells and fibronectin in C33A cells increased (P<0.05). Western blot showed that extracellular S100A7 was detected in culture supernatant of cervical cancer cells. HeLa cells of the experimental group passing through transwell membrane in migration and invasion assays were increased significantly (192.60±24.41 vs 98.80±47.24, P<0.05; 105.40±27.38 vs 84.50±13.51, P<0.05) when the conditional medium was added into the lower compartment of Transwell. Exosomes from C33A cell culture supernatant were extracted successfully, and S100A7 expression was positive. The number of transmembrane C33A cells incubated with exosomes extracted from cells of the experimental group was increased significantly (251.00±49.82 vs 143.00±30.85, P<0.05; 524.60±52.74 vs 389.00±63.23, P<0.05). Conclusion: S100A7 may promote the migration and invasion of cervical cancer cells by epithelial-mesenchymal transition and exosome secretion.

In situ delivery of a curcumin-loaded dynamic hydrogel for the treatment of chronic peripheral neuropathy

Patients with peripheral nerve injuries would highly likely suffer from chronic neuropathic pain even after surgical intervention. The primary reasons for this involve sustained neuroinflammatory and dysfunctional changes in the nervous system after the nerve injury. We previously reported an injectable boronic ester-based hydrogel with inherent antioxidative and nerve protective properties. Herein, we first explored the anti-neuroinflammatory effects of Curcumin on primary sensory neurons and activated macrophages in vitro. Next, we incorporated thiolated Curcumin-Pluronic F-127 micelles (Cur-M) into our boronic ester-based hydrogel to develop an injectable hydrogel that serves as sustained curcumin release system (Gel-Cur-M). By orthotopically injecting the Gel-Cur-M to sciatic nerves of mice with chronic constriction injuries, we found that the bioactive components could remain on the nerves for at least 21 days. In addition, the Gel-Cur-M exhibited superior functions compared to Gel and Cur-M alone, which includes ameliorating hyperalgesia while simultaneously improving locomotor and muscular functions after the nerve injury. This could stem from in situ anti-inflammation, antioxidation, and nerve protection. Furthermore, the Gel-Cur-M also showed extended beneficial effects for preventing the overexpression of TRPV1 as well as microglial activation in the lumbar dorsal root ganglion and spinal cord, respectively, which also contributed to its analgesic effects. The underlying mechanism may involve the suppression of CC chemokine ligand-2 and colony-stimulating factor-1 in the injured sensory neurons. Overall, this study suggests that orthotopic injection of the Gel-Cur-M is a promising therapeutic strategy that especially benefits patients with peripheral neuropathy who require surgical interventions.

Red blood cell membrane-camouflaged poly(lactic-co-glycolic acid) microparticles as a potential controlled release drug delivery system for local stellate ganglion microinjection

The stellate ganglion (SG) is a part of the sympathetic nervous system that has important regulatory effects on several human tissues and organs in the upper body. SG block and intervention have been clinically and preclinically implemented to manage chronic pain in the upper extremities, neck, head, and upper chest as well as chronic heart failure. However, there has been very limited effort to develop and investigate polymer-based drug delivery systems for local delivery to the SG. In this study, we fabricated red blood cell (RBC) membrane-camouflaged poly(lactic-co-glycolic acid) (PLGA) (PLGAM) microparticles for use as a potential long-term controlled release system for local drug delivery. The structure, size, and surface zeta potential results indicated that the spherical PLGAM microparticles were successfully fabricated. Both PLGA and PLGAM microparticles exhibited biocompatibility with human adipose mesenchymal stem cells (ADMSC) and satellite glial cells and showed hemocompatibility. In addition, both PLGA and PLGAM displayed no significant effects on the secretion of proinflammatory cytokines by human monocyte derived macrophages in vitro. We microinjected microparticles into rat SGs and evaluated the retention time of microparticles and the effects of the microparticles on inflammation in vivo over 21 days. Subsequently, we fabricated drug-loaded PLGAM microparticles by using GW2580, a colony stimulating factor-1 receptor inhibitor, as a model drug and assessed its encapsulation efficiency, drug release profiles, biocompatibility, and anti-inflammatory effects in vitro. Our results demonstrated the potential of PLGAM microparticles for long-term controlled local drug release in the SG. STATEMENT OF SIGNIFICANCE: SG block by locally injecting therapeutics to inhibit the activity of the sympathetic nerves provides a valuable benefit to manage chronic pain and chronic heart failure. We describe the fabrication of RBC membrane-camouflaged PLGA microparticles with cytocompatibility, hemocompatibility, and low immunogenicity, and demonstrate that they can be successfully and safely microinjected into rat SGs. The microparticle retention time within SG is over 21 days without eliciting detectable inflammation. Furthermore, we incorporate a CSF-1R inhibitor as a model drug and demonstrate the capacities of long-term drug release and regulation of macrophage functions. The strategies demonstrate the feasibility to locally microinject therapeutics loaded microparticles into SGs and pave the way for further efficacy and disease treatment evaluation.

Multifunctional Microgel-Based Cream Hydrogels for Postoperative Abdominal Adhesion Prevention

Postoperative abdominal adhesions are a common problem after surgery and can produce serious complications. Current antiadhesive strategies focus mostly on physical barriers and are unsatisfactory and inefficient. In this study, we designed and synthesized advanced injectable cream-like hydrogels with multiple functionalities, including rapid gelation, self-healing, antioxidation, anti-inflammation, and anti-cell adhesion. The multifunctional hydrogels were facilely formed by the conjugation reaction of epigallocatechin-3-gallate (EGCG) and hyaluronic acid (HA)-based microgels and poly(vinyl alcohol) (PVA) based on the dynamic boronic ester bond. The physicochemical properties of the hydrogels including antioxidative and anti-inflammatory activities were systematically characterized. A mouse cecum-abdominal wall adhesion model was implemented to investigate the efficacy of our microgel-based hydrogels in preventing postoperative abdominal adhesions. The hydrogels, with a high molecular weight HA, significantly decreased the inflammation, oxidative stress, and fibrosis and reduced the abdominal adhesion formation, compared to the commercial Seprafilm group or Injury-only group. Label-free quantitative proteomics analysis demonstrated that S100A8 and S100A9 expressions were associated with adhesion formation; the microgel-containing hydrogels inhibited these expressions. The microgel-containing hydrogels with multifunctionality decreased the formation of postoperative intra-abdominal adhesions in a murine model, demonstrating promise for clinical applications.

[Changes in percentage of GATA3+ regulatory T cells and their pathogenic roles in allergic rhinitis]

OBJECTIVE

To investigate the changes in percentage of GATA3⁺ regulatory T (Treg) cells in patients with allergic rhinitis (AR) and mouse models.

METHODS

The nasal mucosa specimens were obtained from 6 AR patients and 6 control patients for detection of nasal mucosal inflammation. Peripheral blood mononuclear cells (PBMC) were collected from 12 AP patients and 12 control patients to determine the percentages of Treg cells and GATA3⁺ Treg cells. In a C57BL/6 mouse model of AR, the AR symptom score, peripheral blood OVA-sIgE level, and nasal mucosal inflammation were assessed, and the spleen of mice was collected for detecting the percentages of Treg cells and GATA3⁺ Treg cells and the expressions of Th2 cytokines.

RESULTS

Compared with the control patients, AR patients showed significantly increased eosinophil infiltration and goblet cell proliferation in the nasal mucosa (P < 0.01) and decreased percentages of Treg cells and GATA3⁺ Treg cells (P < 0.05). The mouse models of AR also had more obvious allergic symptoms, significantly increased OVA-sIgE level in peripheral blood, eosinophil infiltration and goblet cell hyperplasia (P < 0.01), markedly lowered percentages of Treg cells and GATA3⁺ Treg cells in the spleen (P < 0.01), and increased expressions of IL-4, IL-6 and IL-10 (P < 0.05).

CONCLUSION

The percentage of GATA3⁺ Treg cells is decreased in AR patients and mouse models. GATA3⁺ Treg cells possibly participate in Th2 cell immune response, both of which are involved in the occurrence and progression of AR, suggesting the potential of GATA3⁺ Treg cells as a new therapeutic target for AR.

[Demographic characteristics and associated influencing factors in treated patients with chronic hepatitis B with hypoviremia : a single-center retrospective cross-sectional study]

Objective: To investigate the demographic characteristics and clinical influencing factors which associates with the occurrence probability of persistent or intermittent hypoviremia (LLV) in patients with chronic hepatitis B (CHB) treated with nucleos(t)ide analogues (NAs). Methods: A single-center retrospective analysis was performed on patients with CHB who received outpatient NAs therapy for≥48 ± 2 weeks. According to the serum hepatitis B virus (HBV) DNA load at 48±2 weeks treatment, the study groups were divided into LLV (HBV DNA < 20 IU/ml and < 2 000 IU/ml) and MVR group (sustained virological response, HBV DNA < 20 IU/ml). Demographic characteristics and clinical data at the start of NAs treatment (considered as baseline) were retrospectively collected for both patient groups. The differences in the reduction of HBV DNA load during treatment was compared between the two groups. Correlation and multivariate analysis were further conducted to analyze the associated factors influencing the LLV occurrence. Statistical analysis was performed using the independent samples t-test, c2 test, Spearman analysis, multivariate logistic regression analysis, or area under the receiver operating characteristic curve. Results: A total of 509 cases were enrolled, with 189 and 320 in the LLV and MVR groups, respectively. Compared to patients with MVR group at baseline: (1) the demographics characteristics of patients showed that LLV group was younger in age (39.1 years, P = 0.027), had a stronger family history (60.3%, P = 0.001), 61.9% received ETV treatment, and higher proportion of compensated cirrhosis (20.6%, P = 0.025) at baseline; (2) the serum virological characteristics of patients showed that LLV group had higher HBV DNA load, qHBsAg level, qHBeAg level, HBeAg positive rate, and the proportion of genotype C HBV infection but decreased HBV DNA during treatment (P < 0.001) at baseline; (3) the biochemical characteristics of patients showed that LLV group had lower serum ALT levels (P = 0.007) at baseline; (4) the noninvasive fibrosis markers of patients showed that LLV group were characterized by high aspartate aminotransferase platelet ratio index (APRI) (P = 0.02) and FIB-4 (P = 0.027) at baseline. HBV DNA, qHBsAg and qHBeAg were positively correlated with LLV occurrence (r = 0.559, 0.344, 0.435, respectively), while age and HBV DNA reduction were negatively correlated (r = -0.098, -0.876, respectively). Logistic regression analysis showed that ETV treatment history, high HBV DNA load at baseline, high qHBsAg level, high qHBeAg level, HBeAg positive, low ALT and HBV DNA level were independent risk factors for patients with CHB who developed LLV with NAs treatment. Multivariate prediction model had a good predictive value for LLV occurrence [AUC 0.922 (95%CI: 0.897 ~ 0.946)]. Conclusion: In this study, 37.1% of CHB patients treated with first-line NAs has LLV. The formation of LLV is influenced by various factors. HBeAg positivity, genotype C HBV infection, high baseline HBV DNA load, high qHBsAg level, high qHBeAg level, high APRI or FIB-4 value, low baseline ALT level, reduced HBV DNA during treatment, concomitant family history, metabolic liver disease history, and age < 40 years old are potential risk factors for developing LLV in patients with CHB during the therapeutic process.

A Dual-network Nerve Adhesive with Enhanced Adhesion Strength Promotes Transected Peripheral Nerve Repair

Peripheral nerve transection has a high prevalence and results in functional loss of affected limbs. The current clinical treatment using suture anastomosis significantly limits nerve recovery due to severe inflammation, secondary damage, and fibrosis. Fibrin glue, a commercial nerve adhesive as an alternative, avoids secondary damage but suffers from poor adhesion strength. To address their limitations, a highly efficacious nerve adhesive based on dual-crosslinking of dopamine-isothiocyanate modified hyaluronic acid and decellularized nerve matrix is reported in this paper. This dual-network nerve adhesive (DNNA) shows controllable gelation behaviors feasible for surgical applications, robust adhesion strength, and promoted axonal outgrowth in vitro. The in vivo therapeutic efficacy is tested using a rat-based sciatic nerve transection model. The DNNA decreases fibrosis and accelerates axon/myelin debris clearance at 10 days post-surgery, compared to suture and commercial fibrin glue treatments. At 10 weeks post-surgery, the strong adhesion and bioactivity allow DNNA to significantly decrease intraneural inflammation and fibrosis, enhance axon connection and remyelination, aid motor and sensory function recovery, as well as improve muscle contraction, compared to suture and fibrin treatments. Overall, this dual-network hydrogel with robust adhesion provides a rapid and highly efficacious nerve transection treatment to facilitate nerve repair and neuromuscular function recovery.

Exercise facilitates regeneration after severe nerve transection and further modulates neural plasticity

Patients with severe traumatic peripheral nerve injury (PNI) always suffer from incomplete recovery and poor functional outcome. Physical exercise-based rehabilitation, as a non-invasive interventional strategy, has been widely acknowledged to improve PNI recovery by promoting nerve regeneration and relieving pain. However, effects of exercise on chronic plastic changes following severe traumatic PNIs have been limitedly discussed. In this study, we created a long-gap sciatic nerve transection followed by autograft bridging in rats and tested the therapeutic functions of treadmill running with low intensity and late initiation. We demonstrated that treadmill running effectively facilitated nerve regeneration and prevented muscle atrophy and thus improved sensorimotor functions and walking performance. Furthermore, exercise could reduce inflammation at the injured nerve as well as prevent the overexpression of TRPV1, a pain sensor, in primary afferent sensory neurons. In the central nervous system, we found that PNI induced transcriptive changes at the ipsilateral lumber spinal dorsal horn, and exercise could reverse the differential expression for genes involved in the Notch signaling pathway. In addition, through neural imaging techniques, we found volumetric, microstructural, metabolite, and neuronal activity changes in supraspinal regions of interest (i.e., somatosensory cortex, motor cortex, hippocampus, etc.) after the PNI, some of which could be reversed through treadmill running. In summary, treadmill running with late initiation could promote recovery from long-gap nerve transection, and while it could reverse maladaptive plasticity after the PNI, exercise may also ameliorate comorbidities, such as chronic pain, mental depression, and anxiety in the long term.

Exosomes derived from differentiated human ADMSC with the Schwann cell phenotype modulate peripheral nerve-related cellular functions

Peripheral nerve regeneration remains a significant clinical challenge due to the unsatisfactory functional recovery and public health burden. Exosomes, especially those derived from mesenchymal stem cells (MSCs), are promising as potential cell-free therapeutics and gene therapy vehicles for promoting neural regeneration. In this study, we reported the differentiation of human adipose derived MSCs (hADMSCs) towards the Schwann cell (SC) phenotype (hADMSC-SCs) and then isolated exosomes from hADMSCs with and without differentiation (i.e., dExo vs uExo). We assessed and compared the effects of uExo and dExo on antioxidative, angiogenic, anti-inflammatory, and axon growth promoting properties by using various peripheral nerve-related cells. Our results demonstrated that hADMSC-SCs secreted more neurotrophic factors and other growth factors, compared to hADMSCs without differentiation. The dExo isolated from hADMSC-SCs protected rat SCs from oxidative stress and enhanced HUVEC migration and angiogenesis. Compared to uExo, dExo also had improved performances in downregulating pro-inflammatory gene expressions and cytokine secretions and promoting axonal growth of sensory neurons differentiated from human induced pluripotent stem cells. Furthermore, microRNA (miRNA) sequencing analysis revealed that exosomes and their parent cells shared some similarities in their miRNA profiles and exosomes displayed a distinct miRNA signature. Many more miRNAs were identified in dExo than in uExo. Several upregulated miRNAs, like miRNA-132-3p and miRNA-199b-5p, were highly related to neuroprotection, anti-inflammation, and angiogenesis. The dExo can effectively modulate various peripheral nerve-related cellular functions and is promising for cell-free biological therapeutics to enhance neural regeneration.

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Exosomes were isolated from hADMSCs with and without differentiation towards SC phenotype (i.e., dExo vs uExo).

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hADMSC-SCs secreted more growth factors compared to hADMSCs without differentiation.

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The dExo protected rat SCs from oxidative stress and enhanced endothelial cell migration and angiogenesis.

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dExo promoted axonal growth of sensory neurons differentiated from hiPSCs.

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miRNA sequencing analysis unveiled and compared the exosomal and cellular miRNA profiles.

Toripalimab (anti-PD-1) versus High-Dose Interferon-α2b as Adjuvant Therapy in Resected Mucosal Melanoma: A Phase II Randomized Trial

BACKGROUND

No standard of care for mucosal melanoma (MM) in the adjuvant setting has been established. Meanwhile, relapse-free survival (RFS) is only about five months after surgery alone. This phase II trial aimed to compare toripalimab vs. high-dose interferon-α2b (HDI) as an adjuvant therapy for resected MM.

PATIENTS AND METHODS

From July 2017 to May 2019, 145 patients with resected MM were randomized (1:1) to receive HDI (N = 72) or toripalimab (N = 73) for one year until disease relapse/distant metastasis, unacceptable toxicity, or withdrawal of consent. The primary endpoint was RFS. The secondary endpoints included distant metastasis-free survival (DMFS), overall survival (OS), and safety.

RESULTS

After a median follow-up of 26.3 months, the numbers of RFS, OS, and DMFS events were 51 vs. 46, 33 vs. 29, and 49 vs. 44 in the toripalimab arm and the HDI arm, respectively. The median RFS were 13.6 (95%CI: 8.31-19.02) months and 13.9 (95%CI: 8.28-19.61) months in the toripalimab arm and HDI arm, respectively. The DMFS was not significantly different between the two arms (HR: 1.00, 95%CI: 0.65-1.54). The median OS was 35.1 months (95%CI: 27.93-NR) in the toripalimab arm, with no significant difference in all-cause death (HR: 1.11, 95% CI: 0.66-1.84) for the two arms. The median sums of the patients' actual infusion doses were 3672 mg and 1054.5 MIU in the toripalimab arm and HDI arm, respectively. The incidence of treatment-emergent adverse events with a grade ≥ 3 was much higher in the HDI arm than in the toripalimab arm (87.5% vs. 27.4%).

CONCLUSION

Toripalimab showed a similar RFS and a more favorable safety profile than HDI, both better than historical data, suggesting that toripalimab might be the better treatment option. However, additional translational studies and better treatment regimens are still warranted to improve the clinical outcome of MM.

3D bioprinted white adipose model for in vitro study of cancer-associated cachexia induced adipose tissue remodeling

Cancer-associated cachexia (CAC) is a complex metabolic and behavioral syndrome with multiple manifestations that involve systemic inflammation, weight loss, and adipose lipolysis. It impacts the quality of life of patients and is the direct cause of death in 20-30% of cancer patients. The severity of fat loss and adipose tissue remodeling negatively correlate with patients' survival outcomes. To address the mechanism of fat loss and design potential approaches to prevent the process, it will be essential to understand CAC pathophysiology through white adipose tissue models. In the present study, an engineered human white adipose tissue (eWAT) model based on three-dimensional (3D) bioprinting was developed and treated with pancreatic cancer cell-conditioned medium (CM) to mimic the status of CAC in vitro. We found that the CM treatment significantly increased the lipolysis and accumulation of the extracellular matrix (ECM). The 3D eWATs were further vascularized to study the influence of vascularization on lipolysis and CAC progression, which was largely unknown. Results demonstrated that CM treatment improved the angiogenesis of vascularized eWATs (veWATs), and veWATs demonstrated decreased glycerol release but increased Ucp1 expression, compared to eWATs. Many unique inflammatory cytokines (IL-8, CXCL-1, GM-CSF, etc) from the CM were detected and supposed to contribute to eWAT lipolysis, Ucp1 up-regulation, and ECM development. In response to CM treatment, eWATs also secreted inflammatory adipokines related to the metastatic ability of cancer, muscle atrophy, and vascularization (NGAL, CD54, IGFBP-2, etc). Our work demonstrated that the eWAT is a robust model for studying cachectic fat loss and the accompanying remodeling of adipose tissue. It is therefore a useful tool for future research exploring CAC physiologies and developing potential therapies.

Regulation of Schwann Cell and DRG Neurite Behaviors within Decellularized Peripheral Nerve Matrix

Decellularized nerve hydrogels (dNHs) containing bioactive molecules are promising biomaterials for peripheral nerve injury (PNI) treatment and have been extensively applied in clinical and preclinical practice. However, most previous research projects studied their influences on nerve-related cellular behaviors in two dimensions (2D) without taking hydrogel biomechanics into consideration. The molecular mechanisms underlying the beneficial microenvironment provided by dNHs also remain unclear. In this study, dNHs from rat sciatic nerves were prepared, and their effects on Schwann cell (SC) and dorsal root ganglion (DRG) neurite behaviors were evaluated and compared to commercial rat tail type I collagen (Col) hydrogels in three-dimensional (3D) environments. We found that dNHs could promote SC proliferation and neurite outgrowth, and both the hydrogel mechanics and components contributed to the dNH functionalization. Through proteomics analysis, we found that laminin (LAM) and type V collagen (COLV) exclusively and abundantly existed in dNHs. By adding exogenous LAM and COLV into Col hydrogels, we demonstrated that they regulated SC gene expression and that LAM could promote SC spreading and neurite outgrowth, while COLV improved SC proliferation. Lastly, dNHs were fabricated into paper-like, aligned nerve scaffolds through unidirectional freezing to expand the dNH applications in PNI treatment.

Application of combined multimodal neuroimaging and video-electroencephalography in intractable epilepsy patients for improved post-surgical outcome prediction

AIM

To investigate the ability of a multidisciplinary approach that combines multimodal neuroimaging with video-electroencephalography (v-EEG) to predict post-surgical outcomes in patients with intractable epilepsy, and explore prognostic predictors for these patients.

MATERIALS AND METHODS

Fifty-eight patients with intractable epilepsy who underwent surgery between March 2016 and October 2019 were reviewed retrospectively. Demographic, clinical, v-EEG, neuroimaging, surgical, and regular follow-up seizure outcome data were collected. Forty-six patients with a follow-up of at least 12 months were graded by Engel scores. Univariate and multivariate analyses were applied to explore prognostic factors that could predict post-surgical seizure outcomes.

RESULTS

Of the 58 patients, 28 were males. The median age was 27 years, the median age at first seizure was 11 years, and the median duration of seizures was 10 years. The Kaplan-Meier log-rank test showed that regardless of whether the follow-up duration was considered, epilepsy type, v-EEG, PET/CT, image post-processing methods, and a multidisciplinary approach that combined multimodal imaging with v-EEG were all correlated with seizure outcomes. Multivariate analysis found that the multidisciplinary approach was an independent predictor of post-surgical outcomes in patients with intractable epilepsy (hazard ratio = 11.400, 95% confidence interval = 2.249-57.787, p=0.003).

CONCLUSIONS

The present study showed that the multidisciplinary approach could provide independent prognostic information for patients with intractable epilepsy undergoing surgery. This approach has strong potential for the easier selection of patients to undergo surgical treatment and accurate prognostication.

Comparative molecular dynamics study on interaction of acetamide and glycerol with phospholipid bilayer

BACKGROUND

The exact mechanisms that acetamide and glycerol interact with cell membrane remains a matter of debate.

OBJECTIVE

To investigate the microscopic interactions of acetamide and glycerol with phospholipid bilayers at various temperatures.

MATERIALS AND METHODS

Molecular dynamics simulations of a hydrated dipalmitoyl-phosphatidylcholine (DPPC) bilayer in the presence of glycerol and acetamide were performed. The system contains 128 lipids and about 700 cryoprotectant molecules, and simulations extended to 15 ns.

RESULT

When compared to glycerol, acetamide shows a stronger affinity with water rather than the lipid bilayer.

CONCLUSION

The knowledge of the mixing dynamics of present system helps to develop better cryoprotective formulas and to propose more optimal cooling/warming protocols.

Implication of microglia in ketamine-induced long-term cognitive impairment in murine pups

BACKGROUND

Ketamine, a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist, is widely applicable to anesthesia, analgesia, and sedation. However, the function and mechanisms of ketamine in the long-term learning and memory function of neonatal mice are unclear.

OBJECTIVE

The present study aims to investigate whether long-term learning and memory function will be affected by multiple ketamine exposures in the early development period.

METHODS

The mRNA and protein levels were measured by RT-qPCR and western blot, respectively. The Morris Water Maze test was performed to assess spatial learning and memory.

RESULTS

We identified that neonatal exposure to ketamine downsized the positive neurons for microtubule-associated protein doublecortin (DCX) and Ki67 in hippocampal dentate gyrus at the juvenile and late adolescence stages. Double-labeling tests demonstrated that the counts of Iba1⁺ cells and Ki67⁺ cells were pronouncedly diminished with exposure to ketamine. Further, qPCR assays to screen the key factors predisposing the populations and maturation of microglia exhibited remarkable decline of CX3CR1 mRNA levels in ketamine group versus the control group. The close relation of microglia to synaptic plasticity was depicted by the significantly downregulated synaptic plasticity-related proteins NR2B and PSD-95 subsequent to multiple exposures to ketamine. Finally, we found that both the protein and mRNA levels of BDNF were markedly decreased in ketamine group versus the control group.

CONCLUSION

We found that multiple exposures to ketamine in neonatal mice lead to spatial learning and memory dysfunction. The alterations of microglial development and function are the possible mechanisms of long-term learning and memory impairment.

Dynamic hyaluronic acid hydrogel with covalent linked gelatin as an anti-oxidative bioink for cartilage tissue engineering

In the past decade, cartilage tissue engineering has arisen as a promising therapeutic option for degenerative joint diseases, such as osteoarthritis, in the hope of restoring the structure and physiological functions. Hydrogels are promising biomaterials for developing engineered scaffolds for cartilage regeneration. However, hydrogel-delivered mesenchymal stem cells or chondrocytes could be exposed to elevated levels of reactive oxygen species (ROS) in the inflammatory microenvironment after being implanted into injured joints, which may affect their phenotype and normal functions and thereby hinder the regeneration efficacy. To attenuate ROS induced side effects, a multifunctional hydrogel with an innate anti-oxidative ability was produced in this study. The hydrogel was rapidly formed through a dynamic covalent bond between phenylboronic acid grafted hyaluronic acid (HA-PBA) and poly(vinyl alcohol) and was further stabilized through a secondary crosslinking between the acrylate moiety on HA-PBA and the free thiol group from thiolated gelatin. The hydrogel is cyto-compatible and injectable and can be used as a bioink for 3D bioprinting. The viscoelastic properties of the hydrogels could be modulated through the hydrogel precursor concentration. The presence of dynamic covalent linkages contributed to its shear-thinning property and thus good printability of the hydrogel, resulting in the fabrication of a porous grid construct and a meniscus like scaffold at high structural fidelity. The bioprinted hydrogel promoted cell adhesion and chondrogenic differentiation of encapsulated rabbit adipose derived mesenchymal stem cells. Meanwhile, the hydrogel supported robust deposition of extracellular matrix components, including glycosaminoglycans and type II collagen, by embedded mouse chondrocytesin vitro. Most importantly, the hydrogel could protect encapsulated chondrocytes from ROS induced downregulation of cartilage-specific anabolic genes (ACAN and COL2) and upregulation of a catabolic gene (MMP13) after incubation with H₂O₂. Furthermore, intra-articular injection of the hydrogel in mice revealed adequate stability and good biocompatibilityin vivo. These results demonstrate that this hydrogel can be used as a novel bioink for the generation of 3D bioprinted constructs with anti-ROS ability to potentially enhance cartilage tissue regeneration in a chronic inflammatory and elevated ROS microenvironment.

The effects of maturation and aging on the rotator cuff tendon-to-bone interface

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area, with a high prevalence for the elderly population, but the underlying reason for this phenomenon is still unknown. The objective of this study is to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging in a mouse model. Four different age groups of mice (newborn, young, adult, and old) were studied. Striking variations of the entheses were observed between the newborn and other matured groups, with collagen content, proteoglycan deposition, collagen fiber dispersion was significantly higher in the newborn group. The compositional and histological features of young, adult, and old groups did not show significant differences, except having increased proteoglycan deposition and thinner collagen fibers at the insertion sites in the old group. Nanoindentation testing showed that the old group had a smaller compressive modulus at the insertion site when compared with other groups. However, tensile mechanical testing reported that the old group demonstrated a significantly higher failure stress when compared with the young and adult groups. The proteomics analysis detected dramatic differences in protein content between newborn and young groups but minor changes among young, adult, and old groups. These results demonstrated: (1) the significant alterations of the enthesis composition and structure occur from the newborn to the young time period; (2) the increased risk of rotator cuff tendon injuries in the elderly population is not solely because of old age alone in the rodent model.

Anisotropic scaffolds for peripheral nerve and spinal cord regeneration

The treatment of long-gap (>10 mm) peripheral nerve injury (PNI) and spinal cord injury (SCI) remains a continuous challenge due to limited native tissue regeneration capabilities. The current clinical strategy of using autografts for PNI suffers from a source shortage, while the pharmacological treatment for SCI presents dissatisfactory results. Tissue engineering, as an alternative, is a promising approach for regenerating peripheral nerves and spinal cords. Through providing a beneficial environment, a scaffold is the primary element in tissue engineering. In particular, scaffolds with anisotropic structures resembling the native extracellular matrix (ECM) can effectively guide neural outgrowth and reconnection. In this review, the anatomy of peripheral nerves and spinal cords, as well as current clinical treatments for PNI and SCI, is first summarized. An overview of the critical components in peripheral nerve and spinal cord tissue engineering and the current status of regeneration approaches are also discussed. Recent advances in the fabrication of anisotropic surface patterns, aligned fibrous substrates, and 3D hydrogel scaffolds, as well as their in vitro and in vivo effects are highlighted. Finally, we summarize potential mechanisms underlying the anisotropic architectures in orienting axonal and glial cell growth, along with their challenges and prospects.

Tannic acid-inspired, self-healing, and dual stimuli responsive dynamic hydrogel with potent antibacterial and anti-oxidative properties

Due to their intrinsic injectable and self-healing characteristics, dynamic hydrogels, based on dynamic covalent bonds, have gained a great attention. In this study, a novel dynamic hydrogel based on the boronic ester dynamic covalent bond is facilely developed using phenylboronic acid-modified hyaluronic acid (HA-PBA) and plant-derived polyphenol-tannic acid (TA). The dynamic hydrogel gelated quickly under mild conditions and had favorable viscoelastic properties with good self-healing and shear-thinning capabilities. Moreover, the simultaneous utilization of TA as a reductant for the green synthesis of silver nanoparticles (AgNP) inspired the preparation of a TA-reduced AgNP hybrid dynamic hydrogel with potent and broad-spectrum antibacterial activities. The dynamic hydrogels could also be applied for pH- and reactive oxygen species (ROS)-responsive release of loaded protein molecules without showing evident cytotoxicity and hemolysis in vitro. In addition, the dynamic hydrogels showed the anti-oxidative properties of high free radical and ROS scavenging capacity, which was verified by the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical assay and ROS fluorescence staining. Overall, this novel class of cytocompatible, self-healing, dual stimuli responsive, antibacterial, anti-oxidative, and injectable hydrogels could be promising as a wound dressing for chronic wound healing.