Colorimetric sensors have been widely used to detect numerous analytes due to their cost-effectiveness, high sensitivity and specificity, and clear visibility, even with the naked eye. In recent years, the emergence of advanced nanomaterials has greatly improved the development of colorimetric sensors. This review focuses on the recent (from the years 2015 to 2022) advances in the design, fabrication, and applications of colorimetric sensors. First, the classification and sensing mechanisms of colorimetric sensors are briefly described, and the design of colorimetric sensors based on several typical nanomaterials, including graphene and its derivatives, metal and metal oxide nanoparticles, DNA nanomaterials, quantum dots, and some other materials are discussed. Then the applications, especially for the detection of metallic and non-metallic ions, proteins, small molecules, gas, virus and bacteria, and DNA/RNA are summarized. Finally, the remaining challenges and future trends in the development of colorimetric sensors are also discussed.
Introduction: Physiologically based pharmacokinetic (PBPK) models for the absorption, disposition, metabolism and excretion (ADME) of nicotine and its major metabolite cotinine in pregnant women (p-PBPK) are rare. The aim of this short research report is to present a p-PBPK model and its simulations for nicotine and cotinine clearance.Methods: The maternal-placental-fetal compartments of the p-PBPK model contain a total of 16 compartments representing major maternal and fetal organs and tissue groups. Qualitative and quantitative data of nicotine and cotinine disposition and clearance have been incorporated into pharmacokinetic parameters.Results: The p-PBPK model reproduced the higher clearance rates of nicotine and cotinine in pregnant women than non-pregnant women. Temporal profiles for their disposition in organs such as the brain were also simulated. Nicotine concentration reaches its maximum value within 2 min after an intravenous injection.Conclusion: The proposed p-PBPK model produces results consistent with available data sources. Further pharmacokinetic experiments are required to calibrate clearance parameters for individual organs, and for the fetus.
Background: The clinical applications of dispensing granules (DG) have increased dramatically. However, it is controversial whether the DG has the same quality and efficacy compared with traditional decoction (TD). In this study, the contents of main compounds, hypoglycemic effects, and potential mechanism of Coptidis Rhizoma (CR) and Scutellaria–coptis (SC), constituted of a 1:1 mixture of CR and Scutellariae Radix (SR), in the forms of TD and DG were compared. Methods: The quantitative analysis was performed on an UPLC-PDA method. The 6-weeks-old male db/db mice were used as Type 2 Diabetes Mellitus (T2DM) mouse modle to investigate the antidiabetic effects of CR and SC in TD form (CR TD and SC TD), as well as CR and SC in DG form (CR DG and SC DG). Results: The total content of five alkaloids in CR TD ranged from 71.00 to 78.62 mg, whereas in CR DG it ranged from 38.77 to 53.68 mg in CR DG per 1 g of decoction pieces. Compared to CR TD, CR DG exhibited a 36% reduction on average. For SC samples, the precipitation occurred in the processing of TD but not in the DG, and the relative ratio of alkaloids to flavonoids was determined to be 1:1 in TD and 1:2 in DG. Furthermore, the animal experiments showed that the CR DG (equivalent to 3 g decoction pieces/kg) had almost the same hypoglycemic effect as CR TD when they were administered for 6 weeks. Compared with SC DG (equivalent to 6 g decoction pieces/kg), SC TD showed a better trend in ameliorating T2DM via ameliorating pancreatic structure and function, and activating Akt/AMPK/GLUT4 signaling pathways. Conclusion: This study indicated that the contents of main compounds were generally higher in CR TD than CR DG originated from the same raw materials. Additionally, changes in the contents of the primary components validated that the compound interactions are exclusive to SC TD during co-decoction, rather than SC DG. The disparate prossing of SC DG and SC TD caused differences both in chemical composition and hypoglycemic effect, suggesting that the substitutability of DG and TD requires further research.
12 May 2025 in Frontiers in Bioengineering and Biotechnology
Introduction: Orthopedic implant failure due to inadequate osseointegration and infection remains a critical challenge. To address this, we engineered a polydopamine (PDA)-mediated dual-functional platform for lithium (Li+) and copper (Cu2+) co-incorporation on titanium alloy (Ti6Al4V) implants, aiming to synergize osteogenic and antibacterial properties through a scalable surface modification strategy.Methods: PDA coatings were polymerized onto polished Ti64 substrates, followed by sequential immersion in LiCl (800 μM) and CuCl2 (10 μM) solutions to construct Li+/Cu2+ co-doped surfaces (PDA@Li 800-Cu 10). In vitro assays assessed MC3T3-E1 pre-osteoblast proliferation (CCK-8), osteogenic differentiation (ALP activity, RT-PCR for ALP/Axin2), and antibacterial activity against S. aureus and E. coli (live/dead staining, CFU assays). In vivo efficacy was evaluated in a rat femoral defect model via micro-CT and histology.Results and discussion: Li+-functionalized surfaces (PDA@Li 800) enhanced osteoblast proliferation and osteogenesis via Wnt/β-catenin activation. Cu2+-loaded coatings (PDA@Cu 10) eradicated >99% bacteria but moderately suppressed osteogenic markers. The dual-doped PDA@Li 800-Cu 10 surface resolved this bioactivity conflict, maintaining antibacterial efficacy comparable to PDA@Cu 10 while elevating the osteogenic capacity of Cu2+-only modified surfaces. In vivo, dual-modified implants eliminated bacterial colonization within 72 h and significantly increased peri-implant bone volume (BV/TV) in comparison to Ti64 controls, outperforming PDA-only counterparts. By harmonizing Li-driven osteoinduction and Cu-mediated bactericidal action through a scalable PDA platform, this work advances a transformative strategy for next-generation orthopedic and dental implants, simultaneously addressing infection risks and bone regeneration demands.