Photostable Small-Molecule NIR-II Fluorescent Scaffolds that Cross the Blood-Brain Barrier for Noninvasive Brain Imaging

The second near-infrared (NIR-II, 1000-1700 nm) fluorescent probes have significant advantages over visible or NIR-I (600-900 nm) imaging for both depth of penetration and level of resolution. Since the blood-brain barrier (BBB) prevents most molecules from entering the central nervous system, NIR-II dyes with large molecular frameworks have limited applications for brain imaging. In this work, we developed a series of boron difluoride (BF₂) formazanate NIR-II dyes, which had tunable photophysical properties, ultrahigh photostability, excellent biological stability, and strong brightness. Modulation of the aniline moiety of BF₂ formazanate dyes significantly enhances their abilities to cross the BBB for noninvasive brain imaging. Furthermore, the intact mouse brain imaging and dynamic dye diffusion across the BBB were monitored using these BF₂ formazanate dyes in the NIR-II region. In murine glioblastoma models, these dyes can differentiate tumors from normal brain tissues. We anticipate that this new type of small molecule will find potential applications in creating probes and drugs relevant to theranostic for brain pathologies.

[Establishment of patient-derived salivary gland basal cell adenoma organoids]

Objective: To establish an in vitro organoid model of human salivary gland basal cell adenoma (BCA). Methods: Fresh tumor sample from a 66-year-old female patient diagnosed with salivary gland BCA was collected from the Dpartment of Oral pathology, Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine in October 2021. And the organoid culture was performed in vitro in a culture medium based on solid droplets of matrix gel, and the growth of the organoid was observed by inverted microscopy. After 14 days, the organoid was fixed in 10% neutral formalin and made into paraffin blocks by agar pre-embedding paraffin embedding method, sectioned. HE staining, morphological observation and immunohistochemical staining of p63, Ki-67, cytokeratin14 (CK14), β-catenin, S-100 and calponin were used for organoids identification. Results: The established BCA organoids were lobulated nodular locally under light microscopy, with deposition of eosinophilic glass-like material around the nests of organoid cells, similar to the morphological architectures of the parental BCA. Immunohistochemistry showed that organoids expressed CK14, p63, and β-catenin in various degree, which was consistent with the immunophenotypic characteristics of the parental BCA tumor cells. Conclusions: An in vitro culture system of BCA organoids was preliminarily established which provides a new model for the study of the pathogenesis of salivary gland tumors.

Unleashing the potential of noncanonical amino acid biosynthesis to create cells with precision tyrosine sulfation

Despite the great promise of genetic code expansion technology to modulate structures and functions of proteins, external addition of ncAAs is required in most cases and it often limits the utility of genetic code expansion technology, especially to noncanonical amino acids (ncAAs) with poor membrane internalization. Here, we report the creation of autonomous cells, both prokaryotic and eukaryotic, with the ability to biosynthesize and genetically encode sulfotyrosine (sTyr), an important protein post-translational modification with low membrane permeability. These engineered cells can produce site-specifically sulfated proteins at a higher yield than cells fed exogenously with the highest level of sTyr reported in the literature. We use these autonomous cells to prepare highly potent thrombin inhibitors with site-specific sulfation. By enhancing ncAA incorporation efficiency, this added ability of cells to biosynthesize ncAAs and genetically incorporate them into proteins greatly extends the utility of genetic code expansion methods.

The bipolar charge plasma spectrometer (BCPS) based on the 2π-field-of-view double-channel electrostatic analyzer

In this paper, we propose a bipolar charge plasma spectrometer based on the double-channel electrostatic analyzer for simultaneously measuring thermal ions and electrons with a 2π hemispherical field-of-view. Both ions and electrons within the wide field-of-view enter the spectrometer, pass through the variable geometric factor channel, and are then separated by the double-channel electric fields. Two microchannel plates are accommodated at the exit of the analyzer for ion and electron detection. The main performance of the spectrometer has been obtained from on-ground calibration. With the electrostatic deflectors and the cylindrically symmetric structure, the spectrometer provides simultaneous measurements of thermal ion and electron velocity distributions with a shared field-of-view of 360° (azimuth angle) by 90° (elevation angle) and a broad energy range for both ions and electrons. The ion analyzer constant and the electron analyzer constant are 11.1 and 9.7, respectively. The detecting energy range of 33.3-44.4 keV for ions and 29.1-38.8 keV for electrons can be obtained by using the sweeping electrostatic analyzer voltage range of 3-4000 V. The ion and electron energy resolutions are 9.6% and 6.1%, respectively. The variable geometric factor function provides a large geometric factor adjusting range for both ion and electron measurements by two orders of magnitude, which fulfills the requirements of a large dynamic flux range for simultaneous measurements of space thermal plasma in the solar wind and magnetosphere.

Video-assisted anal fistula treatment for complex anorectal fistulas in adults: a systematic review and meta-analysis

BACKGROUND

Video-assisted anal fistula treatment (VAAFT) has gained increasing acceptance as a sphincter-sparing procedure for treating complex anorectal fistulas (CAF), but no unequivocal conclusions can yet be drawn regarding its ultimate effectiveness. We reviewed the literature and performed a meta-analysis to evaluate the efficacy and safety of VAAFT in CAF patients.

METHODS

The study protocol was registered with the PROSPERO database (CRD42021279085). A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases up to June 2021 with no restriction on language based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We used the keywords video-assisted surgery, video-assisted anal fistula treatment, and complex anorectal fistula to identify relevant studies.

RESULTS

Fourteen trials (7 prospective and 7 retrospective) with a total of 1201 patients (mean age 43.5 years) were included. The median follow-up duration was 16.5(8-48) months. Pooled analysis showed that the rates of success, recurrence and postoperative complication across the studies were 83% (95% CI 81-85%, I² = 37.9%), 16% (95% CI 14-18%, I² = 4.8%), 11% (95% CI 7-15%, I² = 72.1%), respectively. The postoperative Jorge-Wexner score used to assess the level of anal incontinence was 1.09 (95% CI, 0.9-1.27, I² = 74.6%). The internal opening detection rate was 97.6% (95% CI 96.1-99.6%, I² = 48.2%). Recurrence rates varied according to the closure method of internal opening from 21.4% after using staplers, 18.7% after suturing, to 23.5% after advancement flap. The hospital stay was 3.15 days (95% CI 2.96-3.35, I² = 49.7%). Subgroup analysis indicated that the risk of heterogeneity in the urine retention group was higher  compared with that of the overall group and that retrospective studies may be the source of heterogeneity for postoperative anal incontinence. r . Sensitivity analysis confirmed the stability of the pooled results. Begg's and Egger's tests showed no evidence of publication bias.

CONCLUSIONS

According to the available evidence, VAAFT may be a valuable alternative to fistulotomy or seton in treating CAF and has the additional long-term benefits of reducing anal incontinence and surgical morbidity, permitting earlier healing and accelerated rehabilitation.

Bone-Specific Enhancement of Antibody Therapy for Breast Cancer Metastasis to Bone

Despite the rapid evolution of therapeutic antibodies, their clinical efficacy in the treatment of bone tumors is hampered due to the inadequate pharmacokinetics and poor bone tissue accessibility of these large macromolecules. Here, we show that engineering therapeutic antibodies with bone-homing peptide sequences dramatically enhances their concentrations in the bone metastatic niche, resulting in significantly reduced survival and progression of breast cancer bone metastases. To enhance the bone tumor-targeting ability of engineered antibodies, we introduced varying numbers of bone-homing peptides into permissive sites of the anti-HER2 antibody, trastuzumab. Compared to the unmodified antibody, the engineered antibodies have similar pharmacokinetics and in vitro cytotoxic activity, but exhibit improved bone tumor distribution in vivo. Accordingly, in xenograft models of breast cancer metastasis to bone sites, engineered antibodies with enhanced bone specificity exhibit increased inhibition of both initial bone metastases and secondary multiorgan metastases. Furthermore, this engineering strategy is also applied to prepare bone-targeting antibody-drug conjugates with enhanced therapeutic efficacy. These results demonstrate that adding bone-specific targeting to antibody therapy results in robust bone tumor delivery efficacy. This provides a powerful strategy to overcome the poor accessibility of antibodies to the bone tumors and the consequential resistance to the therapy.

Changes in bone mineral density in Down syndrome individuals: a systematic review and meta-analysis

Data evaluating changes in bone mineral density (BMD) in Down syndrome (DS) individuals remains controversial. Therefore, we conducted a systematic review and meta-analysis to better understand associations between BMD and DS. A systematic literature search of PubMed, EMBASE, Web of Science, and the Cochrane Library up until 1st January 2021 was conducted. We used the keywords "bone mineral density" and "Down Syndrome." Fifteen studies were included. Overall, our results showed a significant decrease in BMD of total body (TB BMD) [MD =  - 0.18; 95% CI (- 0.23 and - 0.12), P < 0.00001, I2 = 89%], total hip (TH BMD) [MD =  - 0.12; 95% CI (- 0.15 and - 0.10), P < 0.00001, I2 = 0%], lumbar spine (LS BMD) [MD =  - 0.12; 95% CI (- 0.14 and - 0.09), P < 0.00001, I2 = 18%], and femoral neck (FN BMD) [MD =  - 0.08; 95% CI (- 0.10 and - 0.06), P < 0.00001, I2 = 0%] in DS individuals when compared with controls. Moreover, the volumetric BMD of lumbar spine (LS vBMD) [MD =  - 0.01; 95% CI (- 0.02 and - 0.01), P = 0.0004, I2 = 19%] also showed a decreasing tendency while the volumetric BMD of the femoral neck (FN vBMD) [MD = 0.01; 95% CI (0.00 and 0.02), P = 0.02, I2 = 0%] was elevated in DS individuals versus controls. These findings demonstrated that individuals with DS had a decreased total and regional (TH, LS, and FN) BMD when compared with the general population. Additionally, when BMD was adjusted for skeletal volume, LS vBMD was also lower, while FN vBMD was elevated in DS individuals versus controls.

Oxime as a general photocage for the design of visible light photo-activatable fluorophores

Photoactivatable fluorophores have been widely used for tracking molecular and cellular dynamics with subdiffraction resolution. In this work, we have prepared a series of photoactivatable probes using the oxime moiety as a new class of photolabile caging group in which the photoactivation process is mediated by a highly efficient photodeoximation reaction. Incorporation of the oxime caging group into fluorophores results in loss of fluorescence. Upon light irradiation in the presence of air, the oxime-caged fluorophores are oxidized to their carbonyl derivatives, restoring strong fluorophore fluorescence. To demonstrate the utility of these oxime-caged fluorophores, we have created probes that target different organelles for live-cell confocal imaging. We also carried out photoactivated localization microscopy (PALM) imaging under physiological conditions using low-power light activation in the absence of cytotoxic additives. Our studies show that oximes represent a new class of visible-light photocages that can be widely used for cellular imaging, sensing, and photo-controlled molecular release.

[Programmed death ligand 1 expression and CD8+T lymphocyte infiltration in salivary gland lymphoepithelial carcinoma]

Objective: To study the expression of programmed death ligand-1 (PD-L1) in tumor cells and CD8⁺T lymphocytes in tumor infiltrating lymphocytes, and to analyze the correlation of PD-L1 expression with infiltration of CD8⁺T lymphocytes and clinicopathologic features in salivary gland lymphoepithelial carcinoma (LEC). Methods: Forty-two cases of primary salivary LECs and 21 cases of secondary salivary LECs were enrolled at the Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University between 2015 and 2017. The expression of Epstein-Barr (EB) virus, PD-L1 and CD8 was examined using chromogenic in situ hybridization (CISH) and immunohistochemistry (IHC) staining. The data were analyzed using SPSS 23.0 software package. Results: EB virus was detected in 61 cases (61/63, 96.8%), including 42 (42/42, 100%) primary LECs and 19 (19/21, 90.5%) secondary LECs. The PD-L1 positive rate (score ≥1) was 97.6% (41/42), and its high-expression rate (score ≥20) was 78.6% (33/42) in primary LECs. The PD-L1 positive rate (score ≥1) was 71.4% (15/21), and its high-expression rate (≥20) was 38.1% (8/21) in secondary LECs. However, the PD-L1 positive rate (score ≥1, P=0.004) and high-expression rate (score ≥20, P=0.001) in primary LECs were higher than those in secondary LECs. There was no difference in the infiltration degree of CD8⁺T lymphocytes between primary and secondary LECs. There was a significant correlation between the expression of PD-L1 and CD8 in primary LECs (P=0.001) and in secondary LECs (P=0.048), respectively. Conclusions: There is PD-L1 expression in primary and secondary salivary LECs, while the expression rate is higher in primary LECs than secondary LECs. The combination of PD-L1 expression and CD8⁺T lymphocytes' presence suggest that most LEC patients might be responsive to immunotherapy, and primary LECs might be more significantly responsive than secondary LECs.