Dicyanopyridine derivatives: One-pot preparation, ACQ-to-AIE transformation, light-conversion quality and photostability.

Low cost and strong fluorescence emission are two important guarantees for luminogens used as light conversion agents. By one-pot multicomponent approach and inexpensive starting materials, three dicyanopyridine (DP) derivatives named as DCP (2-amino-6-methoxy-4-phenylpyridine-3,5-dicarbonitrile), DCO (2-amino-6-methoxy-4-(4-methoxyphenyl) pyridine-3,5-dicarbonitrile) and DCC (2-amino-4-(4-cyanophenyl)-6-methoxypyridine-3,5-dicarbonitrile) were designed and synthesized. Meanwhile, the ACQ-to-AIE transformation was successfully realized by altering substituent groups rather than traditional rotor-stator theory. Based on crystal analysis and theoretical calculations, the ACQ-to-AIE transformation is attributed to the tunable stacking modes and intermolecular weak interactions. Owing to matched fluorescence emission, low lost, high yield, and AIE activity, DCC is used as light conversion agents and doped in EVA matrix. The light conversion quality confirms that DCC can not only convert ultraviolet light, but also significantly improve the transmittance of 25 %/40 % EVA, whose photosynthetic photon flux density at 400-500 nm and 600-700 nm increased to 30.67 %/30.21 % and 25.37 %/37.82 % of the blank film, respectively. After 20 h of UV irradiation (365 nm, 40 W), the fluorescence intensities of DCC films can maintain 92 % of the initial values, indicating good photostability in the doping films. This work not only provides an excellent and low-cost light conversion agent, but also has important significance for ACQ-to-AIE transformation of luminogens.

Revelation of adhesive proteins affecting cellular contractility through reference-free traction force microscopy.

Over the past few decades, the critical role played by cellular contractility associated mechanotransduction in the regulation of cell functions has been revealed. In this case, numerous biomaterials have been chemically or structurally designed to manipulate cell behaviors through the regulation of cellular contractility. In particular, adhesive proteins including fibronectin, poly-L-lysine and collagen type I have been widely applied in various biomaterials to improve cell adhesion. Therefore, clarifying the effects of adhesive proteins on cellular contractility has been valuable for the development of biomaterial design. In this study, reference-free traction force microscopy with a well-organized microdot array was designed and prepared to investigate the relationship between adhesive proteins, cellular contractility, and mechanotransduction. The results showed that fibronectin and collagen type I were able to promote the assembly of focal adhesions and further enhance cellular contraction and YAP activity. In contrast, although poly-L-lysine supported cell spreading and elongation, it was inefficient at inducing cell contractility and activating YAP. Additionally, compared with cellular morphogenesis, cellular contraction was essential for YAP activation.

Semirational Design Based on Consensus Sequences to Balance the Enzyme Activity-Stability Trade-Off.

In this study, the phenomenon of the stability-activity trade-off, which is increasingly recognized in enzyme engineering, was explored. Typically, enhanced stability in enzymes correlates with diminished activity. Utilizing Rosa roxburghii copper-zinc superoxide dismutase (RrCuZnSOD) as a model, single-site mutations were introduced based on a semirational design derived from consensus sequences. The initial set of mutants was selected based on activity, followed by combinatorial mutation. This approach yielded two double-site mutants, D25/A115T (18,688 ± 206 U/mg) and A115T/S135P (18,095 ± 1556 U/mg), exhibiting superior enzymatic properties due to additive and synergistic effects. These mutants demonstrated increased half-lives (T1/2) at 80 °C by 1.2- and 1.6-fold, respectively, and their melting temperatures (Tm) rose by 3.4 and 2.5 °C, respectively, without any loss in activity relative to the wild type. Via an integration of structural analysis and molecular dynamics simulations, we elucidated the underlying mechanism facilitating the concurrent enhancement of both thermostability and enzymatic activity.

Engineering RuBisCO-based shunt for improved cadaverine production in Escherichia coli.

The process of biological fermentation is often accompanied by the release of CO2, resulting in low yield and environmental pollution. Refixing CO2 to the product synthesis pathway is an attractive approach to improve the product yield. Cadaverine is an important diamine used for the synthesis of bio-based polyurethane or polyamide. Here, aiming to increase its final production, a RuBisCO-based shunt consisting of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and phosphoribulate kinase (PRK) was expressed in cadaverine-producing E. coli. This shunt was calculated capable of increasing the maximum theoretical cadaverine yield based on flux model analysis. When a functional RuBisCO-based shunt was established and optimized in E. coli, the cadaverine production and yield of the final engineered strain reached the highest level, which were 84.1 g/L and 0.37 g/g Glucose, respectively. Thus, the design of in situ CO2 fixation provides a green and efficient industrial production process.

Dynamic selection of high-affinity aptamers using a magnetically activated continuous deflection microfluidic chip.

To accelerate the discovery of high-affinity aptamers, a magnetically activated continuous deflection (MACD) chip was designed. The MACD chip could achieve dynamic selection in a continuous flow, which meant that the binding and separation were carried out consecutively. Dynamic selection could make selection efficient. Low-affinity sequences could be eluted in time and high-affinity sequences could be enriched via dynamic selection. The stringency of the conditions could be further increased by lowering the target concentration in the dynamic selection. Finally, a C.al3 aptamer with high-affinity and high-specificity for Candida albicans (C. albicans) was obtained through six rounds of selection. Its dissociation constant (Kd) was 7.9 nM. This demonstrated that dynamic selection using a MACD chip was an effective method for high-affinity aptamer selection.

Oxygenation of Phenols with Water as the Oxygen Source and Oxoammonium Salt as the Oxidant.

Aromatic C-H oxygenation is important in both industrial production and organic synthesis. Here we report a metal-free approach for phenol oxygenation with water as the oxygen source using oxoammonium salts as the renewable oxidant. Employing this protocol, various alkyl-substituted phenols were converted into benzoquinones in yields of 59-98%. On the basis of 18O-labeling and kinetic studies, the hydroxy-oxoammonium adduct was proposed to attack the aromatic ring similarly to electrophilic aromatic substitution. We suppose that the findings described here not only provide an efficient and highly selective protocol for aromatic C-H oxygenation but also may encourage further developments of possible transition-metal-free catalytic methods.

HIV coinfection exacerbates HBV-induced liver fibrogenesis through a HIF-1α- and TGF-ß1-dependent pathway.

BACKGROUND & AIMS: Persons with chronic HBV infection coinfected with HIV experience accelerated progression of liver fibrosis compared to those with HBV monoinfection. We aimed to determine whether HIV and its proteins promote HBV-induced liver fibrosis in HIV/HBV-coinfected cell culture models through HIF-1α and TGF-ß1 signaling. METHODS: The HBV-positive supernatant, purified HBV viral particles, HIV-positive supernatant, or HIV viral particles were directly incubated with cell lines or primary hepatocytes, hepatic stellate cells, and macrophages in mono or 3D spheroid coculture models. Cells were incubated with recombinant cytokines and HIV proteins including gp120. HBV sub-genomic constructs were transfected into NTCP-HepG2 cells. We also evaluated the effects of inhibitor of HIF-1α and HIV gp120 in a HBV carrier mouse model that was generated via hydrodynamic injection of the pAAV/HBV1.2 plasmid into the tail vein of wild-type C57BL/6 mice. RESULTS: We found that HIV and HIV gp120, through engagement with CCR5 and CXCR4 coreceptors, activate AKT and ERK signaling and subsequently upregulate hypoxia-inducible factor-1α (HIF-1α) to increase HBV-induced transforming growth factor-ß1 (TGF-ß1) and profibrogenic gene expression in hepatocytes and hepatic stellate cells. HIV gp120 exacerbates HBV X protein-mediated HIF-1α expression and liver fibrogenesis, which can be alleviated by inhibiting HIF-1α. Conversely, TGF-ß1 upregulates HIF-1α expression and HBV-induced liver fibrogenesis through the SMAD signaling pathway. HIF-1α small-interfering RNA transfection or the HIF-1α inhibitor (acriflavine) blocked HIV-, HBV-, and TGF-ß1-induced fibrogenesis. CONCLUSIONS: Our findings suggest that HIV coinfection exacerbates HBV-induced liver fibrogenesis through enhancement of the positive feedback between HIF-1α and TGF-ß1 via CCR5/CXCR4. HIF-1α represents a novel target for antifibrotic therapeutic development in HBV/HIV coinfection. IMPACT AND IMPLICATIONS: HIV coinfection accelerates the progression of liver fibrosis compared to HBV monoinfection, even among patients with successful suppression of viral load, and there is no sufficient treatment for this disease process. In this study, we found that HIV viral particles and specifically HIV gp120 promote HBV-induced hepatic fibrogenesis via enhancement of the positive feedback between HIF-1α and TGF-ß1, which can be ameliorated by inhibition of HIF-1α. These findings suggest that targeting the HIF-1α pathway can reduce liver fibrogenesis in patients with HIV and HBV coinfection.

Switching the hydrogenation selectivity of urea derivatives via subtly tuning the amount and type of additive in the catalyst system.

Catalytic hydrogenation of urea derivatives is considered to be one of the most feasible methods for indirect reduction functionalization of CO2 and synthesis of valuable chemicals and fuels. Among value-added products, methylamines, formamides and methanol are highly attractive as important industrial raw materials. Herein, we report the highly selective catalytic hydrogenation of urea derivatives to N-monomethylamines for the first time. More importantly, two- and six-electron reduction products can be switched on/off by subtly tuning 0.5 mol% KOtBu (2% to 1.5%): when the molar ratio of KOtBu/(PPh3)3RuCl2 exceeds 2.0, it is favorable for the formation of two-electron reduction products (N-formamides), while when it is below 2.0, the two-electron reduction products are further hydrogenated to six-electron reduction products (N-monomethylamines and methanol). Furthermore, changing the type of additive can also regulate this interesting selectivity. Control experiments showed that this selectivity is achieved by regulating the acid-base environment of the reaction to control the fate of the common hemiaminal intermediate. A feasible mechanism is proposed based on mechanistic experiments and characterization. This method has the advantages of being simple, universal and highly efficient, and opens up a new synthesis strategy for the utilization of renewable carbon sources.

Metal-free production of natural blue colorants through anthocyanin-protein interactions.

INTRODUCTION: The scarcity of naturally available sources for blue colorants has driven reliance on synthetic alternatives. Nevertheless, growing health concerns have prompted the development of naturally derived blue colorants, which remains challenging with limited success thus far. Anthocyanins (ACNs) are known for providing blue colors in plants, and metal complexation with acylated ACNs remains the primary strategy to generate stable blue hues. However, this approach can be costly and raise concerns regarding potential metal consumption risks. OBJECTIVES: Our study aims to introduce a metal-free approach to achieve blue coloration in commonly distributed non-acylated 3-glucoside ACNs by exploring their interactions with proteins and unveiling the underlying mechanisms. METHODS: Using human serum albumin (HSA) as a model protein, we investigated the structural influences of ACNs on their blue color generation using visible absorption spectroscopy, fluorescence quenching, and molecular simulations. Additionally, we examined the bluing effects of six proteins derived from milk and egg and identified the remarkable roles of bovine serum albumin (BSA) and lysozyme (LYS). RESULTS: Our findings highlighted the importance of two or more hydroxyl or methoxyl substituents in the B-ring of ACNs for generating blue colors. Cyanidin-, delphinidin- and petunidin-3-glucoside, featuring two neighboring hydroxyl groups in the B-ring, exhibited blue coloration when interacting with HSA or LYS, driven primarily by favorable enthalpy changes. In contrast, malvidin-3-glucoside, with two methoxyl substituents, achieved blue coloration through interactions with HSA or BSA, where entropy change played significant roles. CONCLUSION: Our work, for the first time, demonstrates the remarkable capability of widely distributed 3-glucoside ACNs to generate diverse blue shades through interactions with certain proteins. This offers a promising and straightforward strategy for the production of ACN-based blue colorants, stimulating further research in this field.

Recycling and high-value utilization of polyethylene terephthalate wastes: A review.

Polyethelene terephthalate (PET) is a well-known thermoplastic, and recycling PET waste is important for the natural environment and human health. This study provides a comprehensive overview of the recycling and reuse of PET waste through energy recovery and physical, chemical, and biological recycling. This article summarizes the recycling methods and the high-value products derived from PET waste, specifically detailing the research progress on regenerated PET prepared by the mechanical recycling of fiber/yarn, fabric, and composite materials, and introduces the application of PET nanofibers recycled by physical dissolution and electrospinning in fields such as filtration, adsorption, electronics, and antibacterial materials. This article explains the energy recovery of PET through thermal decomposition and comprehensively discusses various chemical recycling methods, including the reaction mechanisms, catalysts, conversion efficiencies, and reaction products, with a brief introduction to PET biodegradation using hydrolytic enzymes provided. The analysis and comparison of various recycling methods indicated that the mechanical recycling method yielded PET products with a wide range of applications in composite materials. Electrospinning is a highly promising recycling strategy for fabricating recycled PET nanofibers. Compared to other methods, physical recycling has advantages such as low cost, low energy consumption, high value, simple processing, and environmental friendliness, making it the preferred choice for the recycling and high-value utilization of waste PET.

Association between CT-based adipose variables, preoperative blood biochemical indicators and pathological T stage of clear cell renal cell carcinoma.

Background: Clear cell renal cell carcinoma (ccRCC) is corelated with tumor-associated material (TAM), coagulation system and adipocyte tissue, but the relationships between them have been inconsistent. Our study aimed to explore the cut-off intervals of variables that are non-linearly related to ccRCC pathological T stage for providing clues to understand these discrepancies, and to effectively preoperative risk stratification. Methods: This retrospective analysis included 218 ccRCC patients with a clear pathological T stage between January 1st, 2014, and November 30th, 2021. The patients were categorized into two cohorts based on their pathological T stage: low T stage (T1 and T2) and high T stage (T3 and T4). Abdominal and perirenal fat variables were measured based on preoperative CT images. Blood biochemical indexes from the last time before surgery were also collected. The generalized sum model was used to identify cut-off intervals for nonlinear variables. Results: In specific intervals, fibrinogen levels (FIB) (2.63-4.06 g/L) and platelet (PLT) counts (>200.34 × 109/L) were significantly positively correlated with T stage, while PLT counts (<200.34 × 109/L) were significantly negatively correlated with T stage. Additionally, tumor-associated material exhibited varying degrees of positive correlation with T stage at different cut-off intervals (cut-off value: 90.556 U/mL). Conclusion: Preoperative PLT, FIB and TAM are nonlinearly related to pathological T stage. This study is the first to provide specific cut-off intervals for preoperative variables that are nonlinearly related to ccRCC T stage. These intervals can aid in the risk stratification of ccRCC patients before surgery, allowing for developing a more personalized treatment planning.

Precision-Cut Liver Slices as an ex vivo model to evaluate antifibrotic therapies for liver fibrosis and cirrhosis.

Background: Precision-Cut Liver Slices (PCLS) are an ex vivo culture model developed to study hepatic drug metabolism. One of the main benefits of this model is that it retains the structure and cellular composition of the native liver. PCLS also represents a potential model system to study liver fibrosis in a setting that more closely approximates in vivo pathology than in vitro methods. The aim of this study was to assess whether responses to antifibrotic interventions can be detected and quantified with PCLS. Methods: PCLS of 250 µm thickness were prepared from four different murine fibrotic liver models: choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD), thioacetamide (TAA), diethylnitrosamine (DEN), and carbon tetrachloride (CCl4). PCLS were treated with 5 µM Erlotinib for 72 hours. Histology and gene expression were then compared with in vivo murine experiments and TGF-ß1 activated hepatic stellate cells (HSCs). These types of PCLS characterization were also evaluated in PCLS from human cirrhotic liver. Results: PCLS viability in culture was stable for 72 hours. Treatment of erlotinib, an EGFR inhibitor significantly inhibited the expression of profibrogenic genes Il6, Col1a1 and Timp1 in PCLS from CDAHFD-induced cirrhotic mice, and Il6, Col1a1 and Tgfb1 in PCLS from TAA-induced cirrhotic rats. Erlotinib treatment of PCLS from DEN-induced cirrhotic rats inhibited the expression of Col1a1, Timp1, Tgfb1 and Il6, which was consistent with the impact of erlotinib on Col1a1 and Tgfb1 expression in in vivo DEN-induced cirrhosis. Erlotinib treatment of PCLS from CCl4-induced cirrhosis caused reduced expression of Timp1, Col1a1 and Tgfb1, which was consistent with the effect of erlotinib in in vivo CCl4-induced cirrhosis. In addition, in HSCs at PCLS from normal mice, TGF-ß1 treatment upregulated Acta2 (αSMA), while treatment with erlotinib inhibited the expression of Acta2. Similar expression results were observed in TGF-ß1 treated in vitro HSCs. Expression of MMPs and TIMPs, key regulators of fibrosis progression and regression, were also significantly altered under erlotinib treatment in PCLS. Expression changes under erlotinib treatment were also corroborated with PCLS from human cirrhosis samples. Conclusion: The responses to antifibrotic interventions can be detected and quantified with PCLS at the gene expression level. The antifibrotic effects of erlotinib are consistent between PCLS models of murine cirrhosis and those observed in vivo and in vitro. Similar effects were also reproduced in PCLS derived from patients with cirrhosis. PCLS is an excellent model to assess antifibrotic therapies that is aligned with the principles of Replacement, Reduction and Refinement (3Rs).

Chiral Cell Nanomechanics Originated in Clockwise/Counterclockwise Biofunctional Microarrays to Govern the Nuclear Mechanotransduction of Mesenchymal Stem Cells.

Cell chirality is extremely important for the evolution of cell morphogenesis to manipulate cell performance due to left-right asymmetry. Although chiral micro- and nanoscale biomaterials have been developed to regulate cell functions, how cell chirality affects cell nanomechanics to command nuclear mechanotransduction was ambiguous. In this study, chiral engineered microcircle arrays were prepared by photosensitive cross-linking synthesis on cell culture plates to control the clockwise/counterclockwise geometric topology of stem cells. Asymmetric focal adhesion and cytoskeleton structures could induce chiral cell nanomechanics measured by atomic force microscopy (AFM) nanoindentation in left-/right-handed stem cells. Cell nanomechanics could be enhanced when the construction of mature focal adhesion and the assembly of actin and myosin cytoskeletons were well organized in chiral engineered stem cells. Curvature angles had a negative effect on cell nanomechanics, while cell chirality did not change cytoskeletal mechanics. The biased cytoskeleton tension would engender different nuclear mechanotransductions by yes-associated protein (YAP) evaluation. The chiral stimuli were delivered into the nuclei to oversee nuclear behaviors. A strong cell modulus could activate high nuclear DNA synthesis activity by mechanotransduction. The results will bring the possibility of understanding the interplay of chiral cell nanomechanics and mechanotransduction in nanomedicines and biomaterials.

Comparison of the mid-term clinical efficacy of different fixtaion methods combined with oblique lumbar interbody fusion in treating lumbar degenerative diseases.

BACKGROUND: To compare the mid-term follow-up clinical efficacy among three treatment approaches for lumbar degenerative diseases (LDD): standalone oblique lumbar interbody fusion (SF), oblique lumbar interbody fusion combined with lateral screw fixation (LF), and oblique lumbar interbody fusion combined with posterior screw fixation (PF). METHOD: This retrospective study included a total of 71 cases of single level LDD that underwent OLIF in Hospital of Chengdu University of Traditional Chinese Medicine were retrospectively collected between March 2016 and September 2017. Patients were divided into three groups: 24 cases in the SF group, 24 cases in the LF group and 23 cases in the PF group. Various parameters, such as operation time, hospitalization time, and complications, were recorded. The fusion condition was assessed at last follow up. Clinical outcomes were evaluated using the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) from pre-operation to 5 years post-surgery. RESULTS: Significantly lower mean operation time and hospitalization time were observed in the SF and LF groups compared to the PF group (p < .05). However, no significant difference in fusion rate was found among the three groups. Regarding clinical outcomes, there was no statistically significant difference in VAS scores between the three groups during all follow-up periods. At the 6th month and 1st year after surgery, the SF and LF groups had significantly lower Oswestry Disability Index (ODI) scores compared to the PF group (p < .05). There was no significant difference in perioperative complication rates among the three groups (p > .05). In the LF group, one case of instrument displacement and urethra injury were reported, while in the SF, LF, and PF groups, 10, 9, and 3 cases of cage subsidence were reported, respectively. CONCLUSION: The study findings suggest that oblique lumbar interbody fusion (OLIF) is a safe and effective treatment for mid-term management of lumbar degenerative diseases (LDD). Compared to the posterior screw fixation (PF) group, both the standalone OLIF (SF) and OLIF combined with lateral screw fixation (LF) groups showed advantages in terms of reduced operation time, shorter hospitalization, and faster symptom alleviation in the short-term. However, OLIF combined with PF demonstrated comparable symptom relief in the mid-term and had the additional benefit of lower cage subsidence rates while improving fusion rates as well.

Effect of high pressure homogenization on the interaction between corn starch and cyanidin-3-O-glucoside.

The effects of high pressure homogenization (HPH) at different pressures (50, 100, 150 and 200 MPa) and temperatures (4, 20, 40, 60 and 80 °C) on the interaction between corn starch (CS) and cyanidin-3-O-glucoside (C3G) were investigated. Based on analyses of zeta potential, attenuated total reflection-flourier transformed infrared spectroscopy and binding rate after adding shielding agents, the main interaction force changed from electrostatic interaction to hydrogen bonds. In comparison, the interaction between CS and C3G exhibited greater strength at low temperatures and pressures. Especially, 4 °C/50 MPa HPH caused the most significant enhancement in binding rate and binding amount, from 9.56 % to 25.16 % and 0.96 µg/mg CS to 2.52 µg/mg CS, respectively. At this condition, the specific surface area of CS-C3G increased from 433.57 ± 0.91 m2/kg to 440.93 ± 1.01 m2/kg. Surface fluorescence reduction was observed by confocal laser scanning microscopy, further X-ray diffraction patterns indicated the retention of partial spatial structure. Therefore, HPH opened the entry channels, increased contact area and preserved steric hindrance, which increased hydrogen bonding sites. At high temperatures and high pressures (> 40 °C, > 100 MPa), the increasing free starch chains provided new hydrogen bonding sites. Overall, HPH was an effective method to enhance the interaction by affecting starch structure.

Highly selective NH3 synthesis from N2 on electron-rich Bi0 in a pressurized electrolyzer.

Electrochemical conversion of N2 into ammonia presents a sustainable pathway to produce hydrogen storage carrier but yet requires further advancement in electrocatalyst design and electrolyzer integration. This technology suffers from low selectivity and yield owing to the extremely strong N≡N bond and the exceptionally low solubility of N2 in aqueous systems. A high NH3 synthesis performance is restricted by the high activation energy of N≡N bond and the supply insufficiency of N2 to active sites. This paper describes the introduction of electron-rich Bi0 sites into Ag catalysts with a high-pressure electrolyzer that enables a dramatically enhanced Faradaic efficiency of 44.0% and yield of 28.43 µg cm-2 h-1 at 4.0 MPa. Combined with density functional theory results, in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy demonstrates that N2 reduction reaction follows an associative mechanism, in which a high coverage of N-N bond and -NH2 intermediates suggest electron-rich Bi0 boosts sound activation of N2 molecules and low hydrogenation barrier. The proposed strategy of engineering electrochemical catalysts and devices provides powerful guidelines for achieving industrial-level green ammonia production.

Whole-cell catalyze L-dopa to dopamine via co-expression of transport protein AroP in Escherichia coli.

Dopamine is high-value compound of pharmaceutical interest, but its industrial scale production mostly focuses on chemical synthesis, possessing environment pollution. Bio-manufacturing has caused much attention for its environmental characteristic. Resting cells were employed to as biocatalysts with extraordinary advantages like offering stable surroundings, the inherent presence of expensive cofactors. In this study, whole-cell bioconversion was employed to convert dopa to dopamine. To increase the titer and yield of dopamine production through whole-cell catalysis, three kinds of aromatic amino acid transport protein, AroP, PheP and TyrP, were selected to be co-expressed. The effects of the concentration of L-dopa, pyridoxal-5'- phosphate (PLP), reaction temperature and pH were characterized for improvement of bioconversion. Under optimal conditions, dopamine titer reached 1.44 g/L with molar yield of 46.3%, which is 6.62 times than that of initial conditions. The catalysis productivity of recombinant E. coli co-expressed L-dopa decarboxylase(DDC) and AroP was further enhanced by repeated cell recycling, which maintained over 50% of its initial ability with eight consecutive catalyses. This study was the first to successfully bioconversion of dopamine by whole-cell catalysis. This research provided reference for whole-cell catalysis which is hindered by cell membrane.

A PDA-Functionalized 3D Lung Scaffold Bioplatform to Construct Complicated Breast Tumor Microenvironment for Anticancer Drug Screening and Immunotherapy.

2D cell culture occupies an important place in cancer progression and drug discovery research. However, it limitedly models the "true biology" of tumors in vivo. 3D tumor culture systems can better mimic tumor characteristics for anticancer drug discovery but still maintain great challenges. Herein, polydopamine (PDA)-modified decellularized lung scaffolds are designed and can serve as a functional biosystem to study tumor progression and anticancer drug screening, as well as mimic the tumor microenvironment. PDA-modified scaffolds with strong hydrophilicity and excellent cell compatibility can promote cell growth and proliferation. After 96 h treatment with 5-FU, cisplatin, and DOX, higher survival rates in PDA-modified scaffolds are observed compared to nonmodified scaffolds and 2D systems. The E-cadhesion formation, HIF-1α-mediated senescence decrease, and tumor stemness enhancement can drive drug resistance and antitumor drug screening of breast cancer cells. Moreover, there is a higher survival rate of CD45+ /CD3+ /CD4+ /CD8+ T cells in PDA-modified scaffolds for potential cancer immunotherapy drug screening. This PDA-modified tumor bioplatform will supply some promising information for studying tumor progression, overcoming tumor resistance, and screening tumor immunotherapy drugs.