A dynamic nomogram for predicting pathologic complete response to neoadjuvant chemotherapy in locally advanced rectal cancer.

AIM: To explore the clinical factors associated with pathologic complete response (pCR) for locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) and develop a web-based dynamic nomogram. METHODS: Retrospective analysis of patients with examination confirmed LARC from 2011 to 2022. Patients from the Union Hospital of Fujian Medical University were included as the training cohort (n = 1579) and Zhangzhou Hospital of Fujian Medical University as the external validation cohort (n = 246). RESULTS: In the training cohort, after nCRT, 350 (22.2%) patients achieved pCR. More stomas were avoided in pCR patients (73.9% vs. 69.7%, p = 0.043). After a median follow-up time of 47.7 months (IQR 2-145) shown OS (5-year: 93.7% vs. 81.0%, HR = 0.310, 95%CI: 0.189-0.510, p < 0.001) and DFS (5-year: 91.2% vs. 75.0%, HR = 0.204, 95%CI: 0.216-0.484, p < 0.001) were significantly better among patients with pCR than non-pCR. Multivariable Logistic analysis shown pCR was significantly associated with Pre-CRT CEA (HR = 0.944, 95%CI: 0.921-0.968; p < 0.001), histopathology (HR = 4.608, 95%CI: 2.625-8.089; p < 0.001), Pre-CRT T stage (HR = 0.793, 95%CI: 0.634-0.993; p = 0.043), Pre-CRT N stage (HR = 0.727, 95%CI: 0.606-0.873; p = 0.001), Pre-CRT MRI EMVI (HR = 0.352, 95%CI: 0.262-0.473; p < 0.001), total neoadjuvant therapy (HR = 2.264, 95%CI: 1.280-4.004; p = 0.005). Meanwhile, the online version of the nomogram established in this study was publicized on an open-access website (URL: https://pcrpredict.shinyapps.io/LARC2/). The model predicted accuracy with a C-index of 0.73 (95% CI: 0.70-0.75), with an average C-index of 0.73 for the internal cross validation and 0.78 (95% CI: 0.72-0.83) for the external validation cohort, showing excellent model accuracy. Delong test results showed the model has an important gain value for clinical characteristics to predict pCR in rectal cancer. CONCLUSIONS: Patients with pCR had a better prognosis, including OS and DFS, and were independently associated with Pre-CRT CEA, histopathology, Pre-CRT T/N stage, Pre-CRT MRI EMVI, and TNT. A web-based dynamic nomogram was successfully established for clinical use at any time.

Local resection versus radical resection after neoadjuvant chemoradiotherapy for patients with locally advanced rectal cancer: a propensity-score matched cohort analysis.

BACKGROUND: We aimed to address the shortage of evidence regarding the safety of the local resection approach by comparing long-term oncological outcomes between patients managed by local resection and those who underwent radical resection. METHODS: This was a propensity-score matched cohort analysis study that included patients of all ages diagnosed with locally advanced rectal cancer (LARC) who had received neoadjuvant chemoradiotherapy (nCRT) at the Fujian Medical University Union Hospital and Fujian Medical University Affiliated Zhangzhou Hospital, China, between Jan 10, 2011, to Dec 28, 2021. Partial patients with a significant downstage of the tumor were offered management with the local resection approach, and most of the rest were offered radical resection if eligible. FINDINGS: One thousand six hundred ninety-three patients underwent radical resection after nCRT, and another 60 patients performed local resection. The median follow-up times were 44.0 months (interquartile range = 4-107 months). After propensity-core matching (PSM), in the Kaplan-Meier curves, local resection (n = 56) or radical resection (n = 211) was not significantly associated with 1-, 3-, and 5-year cumulative incidence of overall survival (OS) (HR = 1.103, 95% CI: 0.372 ~ 3.266), disease-free survival (DFS) ((HR = 0.972, 95% CI: 0.401 ~ 2.359), local recurrence (HR = 1.044, 95% CI: 0.225 ~ 4.847), and distant metastasis (HR = 0.818, 95% CI: 0.280 ~ 2.387) (all log-rank P > 0.05). Similarly, multivariate Cox regression analysis indicates that local excision still was not an independent risk factor for OS (HR = 0.863, 95% CI: 0.267 ~ 2.785, P = 0.805) and DFS (HR = 0.885, 95% CI: 0.353 ~ 2.215, p = 0.794). CONCLUSION: Local resection can be a management option in selected patients with middle-low rectal cancer after nCRT for LARC and without loss of oncological safety at five years.

Development and validation of neoadjuvant rectal score-based signature nomograms to predict overall survival and disease-free survival in locally advanced rectal cancer: a retrospective, double center, cohort study.

AIM: To evaluate the prognostic significance of the NAR score and develop nomograms for locally advanced rectal cancer (LARC) treated after neoadjuvant chemo-radiotherapy (nCRT) combined with total meso-rectal excision (TME) surgery to predict prognostic. METHODS: Retrospective collection among LARC patients treated at Fujian Medical University Union Hospital (training cohort) and Fujian Medical University Affiliated Zhangzhou Hospital (external validation cohort) between Jan 10, 2011 and Dec 28, 2021. The NAR score was calculated by formula: [5pN-3(cT-pT) + 12]^2/9.61. NAR score low (< 8), intermediate (8-16), and high (> 16). RESULTS: 1665 patients in the training cohort and 256 patients in the external validation cohorts were enrolled. Lower NAR score was significantly associated with better cumulative incidence of OS, DFS, local recurrence (LR), and distant metastasis (DM) (all P < 0.001). Multivariate Cox regression analysis indicates that NAR score, distance to the anal verge, no.253 LN metastasis, post-CRT carbohydrate antigen 19-9, tumor regression grade, and surgery method are independent predictors of OS and DFS (all P < 0.001). Among these independent factors, the NAR score had the highest area under the curve (AUC) and the nomograms to predict OS and DFS were generated. The AUCs for the accuracy of the prediction OS were 1 year = 0.742, 3 years = 0.749, 5 years = 0.713; prediction DFS were 1 year = 0.727, 3 years = 0.739, 5 years = 0.718, the models have good accuracy. CONCLUSIONS: The NAR score can effectively classify patients with LARC into groups with varying outcomes of OS, DFS, LR, and DM. Moreover, the novel nomograms comprising the NAR score were developed and validated to help predict OS and DFS.

A nomogram for predicting good response after neoadjuvant chemoradiotherapy for locally advanced rectal cancer: a retrospective, double-center, cohort study.

AIM: The purpose of this study was to explore the clinical factors associated with achieving good response after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to develop and validate a nomogram. METHODS: A total of 1724 consecutive LARC patients treated at Fujian Medical University Union Hospital from January 2010 to December 2021 were retrospectively evaluated as the training cohort; 267 consecutive LARC patients treated at Zhangzhou Affiliated Hospital of Fujian Medical University during the same period were evaluated as the external 2 cohorts. Based on the pathological results after radical surgery, treatment response was defined as follows: good response, stage ypT0∼2N0M0 and poor response, ypT3∼4N0M0 and/or N positive. Independent influencing factors were analyzed by logistic regression, a nomogram was developed and validated, and the model was evaluated using internal and external data cohorts for validation. RESULTS: In the training cohort, 46.6% of patients achieved good response after nCRT combined with radical surgery. The rate of the retained anus was higher in the good response group (93.5% vs. 90.7%, P < 0.001). Cox regression analysis showed that the risk of overall survival and disease-free survival was significantly lower among good response patients than poor response patients, HR = 0.204 (95%CI: 0.146-0.287). Multivariate logistic regression analysis showed an independent association with 9 clinical factors, including histopathology, and a nomogram with an excellent predictive response was developed accordingly. The C-index of the predictive accuracy of the nomogram was 0.764 (95%CI: 0.742-0.786), the internal validation of the 200 bootstrap replication mean C-index was 0.764, and the external validation cohort showed an accuracy C-index of 0.789 (95%CI: 0.734-0.844), with good accuracy of the model. CONCLUSION: We identified factors associated with achieving good response in LARC after treatment with nCRT and developed a nomogram to contribute to clinical decision-making.

Sustained delivery of BMP-2 enhanced osteoblastic differentiation of BMSCs based on surface hydroxyapatite nanostructure in chitosan-HAp scaffold.

The surface characteristics of biomaterials, especially regarding the sustained delivery of bone morphogenetic protein-2 (BMP-2), can possibly provide a novel and effective drug delivery system that can enhance osteogenesis. In this study, we evaluated the BMP-2 adsorption and release ability of the surface biomimetic hydroxyapatite (HAp) nanostructure on a new HAp-coated genipin-chitosan conjugation scaffold (HGCCS), and the resulting osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. HGCCS exhibited a loading efficiency of 65% (1.30 µg), which is significantly higher than 28% (0.56 µg, p < 0.01) for the genipin cross-linked chitosan framework, as quantified by an enzyme-linked immunosorbent assay. More importantly, we found that the release of BMP-2 from HGGCS sustained for at least 14 days in simulated body fluid in vitro, which is much better than the burst release within 3 days for CGF. Moreover, the BMP-2 release from HGCCS induced an increase in alkaline phosphatase activity as an indicator of osteogenic differentiation of seeded BMSCs for 14 days in vitro. HGCCS also stimulated a high mRNA expression of osteogenic differentiation makers, runt-related transcription factor 2 for 14 days, osteopontin for 3 days, and osteocalcin for 14 days. The results of this study suggest that the surface biomimetic HAp nanostructure of HGCCS used as a delivery system for BMP-2 is capable of promoting osteogenic differentiation in vitro. These findings demonstrated that HAp nanostructure assembled on organic porous scaffold could work as both calcium source and absorption/release platform, which opened a new research avenue for cell growth factor release, and provided a promising strategy for design and preparation of bioactive scaffold for bone tissue engineering.

Carbodiimide crosslinked collagen from porcine dermal matrix for high-strength tissue engineering scaffold.

Naturally-derived collagens for tissue engineering are limited by low mechanical strength and rapid degradation. In this study, carbodiimide is used to chemically modify the collagen derived from porcine acellular dermal matrix (PADM). The results show that the strength and resistance of PADM to enzymatic digestion can be adjusted by the reconnection of free amino and carboxyl groups of the collagen fibers. The cytocompatibility of the crosslinked PADM was evaluated by cell adhesion and proliferation assays. The cell culture studies on crosslinked and uncrosslinked PADM showed that the modification does not affect the scaffold's biocompatibility. These results demonstrate that the PADM collagen materials can be strengthened through a low-cost, non-toxic crosslinking method for potential use in biomedical applications.

Enhancement of electrochemical differentiation ability of nucleobases in phosphate buffer solution at pH 7.4.

The electrochemical behavior of nucleobases has been studied in 0.1 M phosphate buffer solution at pH 7.4, using a bare graphite electrode. Guanine and adenine produced well-defined oxidation peaks at about +0.63 and +0.91 V at 100 mV/s, respectively. Nucleobases exhibit an irreversible and hybrid-controlled electrochemical process, including adsorption and diffusion. The nucleobase oxidation peaks shift due to the selective interactions of nucleobases with each other. The oxidation peaks for three different pyrimidine bases, uracil, cytosine, and thymine, can be clearly identified at +1.26, +1.41, and +1.32 V, respectively. These differences in the electrochemical behavior among nucleobases can be attributed to their different chemical structures.

Ultrasonic irradiation assisted surface modification of titanium plates to improve MC3T3-E1 cell proliferation.

The surface modification of titanium implants by NaOH has been widely investigated to improve their biocompatibility and bioactivity. It is very important to prepare an even network structure on titanium implants. In this work, ultrasonic irradiation (UI) is used along two different routes to obtain several modified surfaces on titanium plates: (1) the plates are first treated by a NaOH solution, and then UI is used to wash them in double distilled water; (2) the plates are modified by a NaOH solution in an ultrasonic cleaner with UI at 50 W. It is demonstrated that the UI energy can easily remove any weakly bound layers (WBL) on the titanium surface, leaving a strongly bound layer (SBL). The SBL is shown to enhance the proliferation of MC3T3-E1 preosteoblasts in comparison with the WBL. A dense and uniformly distributed nanostructure layer can be synthesized in situ on the surface of metallic titanium through a reaction between a NaOH solution and titanium under UI. The titanium plates prepared with NaOH and UI show better proliferation of preosteoblasts than titanium without UI.

In vitro investigation on the biodegradability and biocompatibility of genipin cross-linked porcine acellular dermal matrix with intrinsic fluorescence.

As a biocompatible and bioactive natural tissue engineering scaffold, porcine acellular dermal matrix (PADM) has limitations for the application in tissue regeneration due to its low strength and rapid biodegradation. Here, purified PADM was modified by a nontoxic cross-linker (genipin) to enhance its mechanical properties and improve its resistance to enzymatic degradation. In vitro testing results demonstrated that the stiffness of the genipin cross-linked PADM was improved and biodegradation rate was decreased. Results of cell proliferation assays showed that the cross-linking reaction by genipin did not undermine the cytocompatibility of PADM. Furthermore, genipin cross-linking imparted an observable fluorescence allowing visualization of the scaffold's three-dimensional (3D) porous structure and cell distribution by confocal laser scanning microscopy (CLSM). Immunostaining of the cell nuclei and cytoskeleton indicated that MC3T3-E1 preosteoblasts were tightly adhered to and uniformly distributed onto the cross-linked PADM scaffold. Results of this study suggest that the 3D porous genipin cross-linked PADM with intrinsic fluorescence may have broader applications for tissue engineering scaffolds where higher mechanical stiffness is needed.

Bone repair by periodontal ligament stem cellseeded nanohydroxyapatite-chitosan scaffold.

BACKGROUND: A nanohydroxyapatite-coated chitosan scaffold has been developed in recent years, but the effect of this composite scaffold on the viability and differentiation of periodontal ligament stem cells (PDLSCs) and bone repair is still unknown. This study explored the behavior of PDLSCs on a new nanohydroxyapatite-coated genipin-chitosan conjunction scaffold (HGCCS) in vitro as compared with an uncoated genipin-chitosan framework, and evaluated the effect of PDLSC-seeded HGCCS on bone repair in vivo. METHODS: Human PDLSCs were cultured and identified, seeded on a HGCCS and on a genipin-chitosan framework, and assessed by scanning electron microscopy, confocal laser scanning microscopy, MTT, alkaline phosphatase activity, and quantitative real-time polymerase chain reaction at different time intervals. Moreover, PDLSC-seeded scaffolds were used in a rat calvarial defect model, and new bone formation was assessed by hematoxylin and eosin staining at 12 weeks postoperatively. RESULTS: PDLSCs were clonogenic and positive for STRO-1. They had the capacity to undergo osteogenic and adipogenic differentiation in vitro. When seeded on HGCCS, PDLSCs exhibited significantly greater viability, alkaline phosphatase activity, and upregulated the bone-related markers, bone sialoprotein, osteopontin, and osteocalcin to a greater extent compared with PDLSCs seeded on the genipin-chitosan framework. The use of PDLSC-seeded HGCCS promoted calvarial bone repair. CONCLUSION: This study demonstrates the potential of HGCCS combined with PDLSCs as a promising tool for bone regeneration.

High ethanol sensitivity of palladium/TiO2 nanobelt surface heterostructures dominated by enlarged surface area and nano-Schottky junctions.

TiO(2) nanobelts were prepared by the hydrothermal growth method. The surface of the nanobelts was coarsened by selective acid corrosion and functionalized with Pd catalyst particles. Three nanobelt samples (TiO(2) nanobelts, surface-coarsened TiO(2) nanobelts and Pd nanoparticle/TiO(2) nanobelt surface heterostructures) were configured as gas sensors and their sensing ability was measured. Both the surface-coarsened nanobelts and the Pd nanoparticle-decorated TiO(2) nanobelts exhibited dramatically improved sensitivity to ethanol vapor. Pd nanoparticle-decorated TiO(2) nanobelts with surface heterostructures exhibited the best sensitivity, selectivity, working temperature, response/recovery time, and reproducibility. The excellent ethanol sensing performance is attributed to the large surface area and enhancement by Schottky barrier-type junctions between the Pd nanoparticles and TiO(2) nanobelts.

Nanopaper based on Ag/TiO2 nanobelts heterostructure for continuous-flow photocatalytic treatment of liquid and gas phase pollutants.

The Ag/TiO(2) nanobelt heterostructures were prepared by the acid-assisted hydrothermal method followed by an in situ photo-reduction process. The photocatalytic activity of TiO(2) nanobelts was evidently enhanced by the heterostructures between Ag nanoparticles and TiO(2) nanobelts. The nanopapers based on Ag/TiO(2) nanobelt heterostructures were fabricated via a modified paper-making process. A novel continuous photocatalytic reactor was designed, and MO removal rate of Ag/C-TiO(2) nanopaper was achieved to 100% in 40 min for single layer and only in 6 min for three layers. The self-supported TiO(2) nanopapers with porous structures also showed an excellent continuous photocatalytic performance for toluene gas under UV light irradiation, and the corresponding degradation rate was 69.5% in 184 min. Moreover, the Ag/TiO(2) nanobelts nanopaper showed a good antibacterial effect. The multifunctional TiO(2) nanopapers modified by the heterostuctures could have potential applications in the environmental and biomaterial fields.

Construction of a fluorescent nanostructured chitosan-hydroxyapatite scaffold by nanocrystallon induced biomimetic mineralization and its cell biocompatibility.

Biomaterial surfaces and their nanostructures can significantly influence cell growth and viability. Thus, manipulating surface characteristics of scaffolds can be a potential strategy to control cell functions for stem cell tissue engineering. In this study, in order to construct a hydroxyapatite (HAp) coated genipin-chitosan conjugation scaffold (HGCCS) with a well-defined HAp nanostructured surface, we have developed a simple and controllable approach that allows construction of a two-level, three-dimensional (3D) networked structure to provide sufficient calcium source and achieve desired mechanical function and mass transport (permeability and diffusion) properties. Using a nontoxic cross-linker (genipin) and a nanocrystallon induced biomimetic mineralization method, we first assembled a layer of HAp network-like nanostructure on a 3D porous chitosan-based framework. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis confirm that the continuous network-like nanostructure on the channel surface of the HGCCS is composed of crystalline HAp. Compressive testing demonstrated that the strength of the HGCCS is apparently enhanced because of the strong cross-linking of genipin and the resulting reinforcement of the HAp nanonetwork. The fluorescence properties of genipin-chitosan conjugation for convenient monitoring of the 3D porous scaffold biodegradability and cell localization in the scaffold was specifically explored using confocal laser scanning microscopy (CLSM). Furthermore, through scanning electron microscope (SEM) observation and immunofluorescence measurements of F-actin, we found that the HAp network-like nanostructure on the surface of the HGCCS can influence the morphology and integrin-mediated cytoskeleton organization of rat bone marrow-derived mesenchymal stem cells (BMSCs). Based on cell proliferation assays, rat BMSCs tend to have higher viability on HGCCS in vitro. The results of this study suggest that the fluorescent two-level 3D nanostructured chitosan-HAp scaffold will be a promising scaffold for bone tissue engineering application.

A 2,7-carbazole-based dicationic salt for fluorescence detection of nucleic acids and two-photon fluorescence imaging of RNA in nucleoli and cytoplasm.

A new carbazole-derived dicationic compound, namely 2,7-bis(1-hydroxyethyl-4-vinylpyridinium iodine)-N-ethylcarbazole (2,7-9E-BHVC), with a large two-photon action absorption cross section in nucleic acids has been obtained. Moreover, it possesses the potential of imaging RNA in nucleoli and cytoplasm in two-photon fluorescence microscopy and exhibits good counterstain compatibility with the commercial fluorescent nucleic dye DAPI.

In vitro assessment of the differentiation potential of bone marrow-derived mesenchymal stem cells on genipin-chitosan conjugation scaffold with surface hydroxyapatite nanostructure for bone tissue engineering.

Increasing evidence has revealed that the surface characteristics of biomaterials, such as chemical composition, stiffness, and topography, especially nanotopography, significantly influence cell growth and differentiation. In this study, we examined the effect of surface biomimetic apatite nanostructure of a new hydroxyapatite-coated genipin-chitosan conjugation scaffold (HGCCS) on cell shape, cytoskeleton organization, and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells in vitro. Cell shape and cytoskeleton organization showed significant differences between cells cultured on genipin-cross-linked chitosan framework and those cultured on HGCCS with surface apatite network-like nanostructure after 7 days of incubation in the osteogenic medium. The result of specific alkaline phosphatase activity as an indicator of osteogenic differentiation showed that the alkaline phosphatase activity of rat bone marrow-derived mesenchymal stem cells was higher on HGCCS. Based on quantitative real-time polymerase chain reaction, HGCCS induced highest mRNA expression of osteogenic differentiation makers, runt-related transcription factor 2 by 7 days, osteopontin by 7 days, and osteocalcin by 14 days, respectively. The enhanced ability of cells on HGCCS to produce mineralized extracellular matrix and nodules was also assessed on day 14 with Alizarin red staining. The results of this study suggest that the surface biomimetic apatite nanostructure of HGCCS is a critical signal cue to promoting osteogenic differentiation in vitro. These findings open a new research avenue to controlling stem cell lineage commitment and provide a promising scaffold for bone tissue engineering.

A series of carbazole cationic compounds with large two-photon absorption cross sections for imaging mitochondria in living cells with two-photon fluorescence microscopy.

A series of carbazole cationic compounds based on donor- Π-acceptor (D-Π-A) structure were synthesized and characterized. They exhibit large two-photon absorption cross sections when excited by a 810 nm a laser beam, and their photophysical properties show that the intramolecular charge transfer (ICT) character is predominant. Moreover these compounds can easily pass though the intact cell membrane of living cells, amongst, 3-(1-hydroxyethyl-4-vinylpyridium iodine)-N-butyl carbazole (9B-HVC) has been proven to be capable of accumulating within the mitochondria possessing large membrane potential and imaging this organelle in living cells by means of two-photon fluorescence microscopy. At the same time usable fluorescent photos can be obtained at lower incident excitation power (5 mW) and low-micromolar concentrations (2 µM), which does not result in significant reduction in cell viability over a period of at least 24 h.

In vitro biomimetic construction of hydroxyapatite-porcine acellular dermal matrix composite scaffold for MC3T3-E1 preosteoblast culture.

The application of porous hydroxyapatite-collagen (HAp-Collagen) as a bone tissue engineering scaffold is hindered by two main problems: its high cost and low initial strength. As a native 3-dimenssional collagen framework, purified porcine acellular dermal matrix (PADM) has been successfully used as a skin tissue engineering scaffold. Here we report its application as a matrix for the preparation of HAp to produce a bone tissue scaffold through a biomimetic chemical process. The HAp-PADM scaffold has two-level pore structure, with large channels (∼100 µm in diameter) inherited from the purified PADM microstructure and small pores (<100 nm in diameter) formed by self-assembled HAp on the channel surfaces. The obtained HAp-PADM scaffold (S15D) has a compressive elastic modulus as high as 600 kPa. The presence of HAp in sample S15D reduces the degradation rate of PADM in collagenase solution at 37°C. After 7 day culture of MC3T3-E1 pre-osteroblasts, MTT data show no statistically significant difference on pure PADM framework and HAp-PADM scaffold (p > 0.05). Because of its high strength and nontoxicity, its simple preparation method, and designable and tailorable properties, the HAp-PADM scaffold is expected to have great potential applications in medical treatment of bone defects.