The Royal Society of Chemistry最新文献

Somatic cell nuclear transfer (SCNT), referred to as somatic cell cloning, is a pivotal biotechnological technique utilized across various applications. Although robotic SCNT is currently available, the subsequent oocyte electrical activation/reconstructed embryo electrofusion is still manually completed by skilled operators, presenting challenges in efficient manipulation due to the uncontrollable positioning of the reconstructed embryo. This study introduces a robotic SCNT-electrofusion system to enable high-precision batch SCNT cloning. The proposed system integrates optical tweezers and microfluidic technologies. An optical tweezer is employed to facilitate somatic cells in precisely reaching the fusion site, and a specific polydimethylsiloxane (PDMS) chip is designed to assist in positioning and pairing oocytes and somatic cells. Enhancement in the electric field distribution between two parallel electrodes by PDMS pillars significantly reduces the required external voltage for electrofusion/electrical activation. We employed porcine oocytes and porcine fetal fibroblasts for SCNT experiments. The experimental results show that 90.56% of oocytes successfully paired with somatic cells to form reconstructed embryos, 76.43% of the reconstructed embryos successfully fused, and 70.55% of these embryos underwent cleavage. It demonstrates that the present system achieves the robotic implementation of oocyte electrical activation/reconstructed embryo electrofusion. By leveraging the advantages of batch operations using microfluidics, it proposes an innovative robotic cloning procedure that scales embryo cloning.

Recently, owing to their special spatial structures, peptide-based macrocycles have shown tremendous promise and aroused great interest in multidisciplinary research ranging from potent antibiotics against resistant strains to functional biomaterials with novel properties. Besides traditional monocyclic peptides, many fascinating polycyclic and remarkable higher-order cyclic, spherical and cylindric peptidic systems have come into the limelight owing to breakthroughs in various chemical (e.g., native chemical ligation and transition metal catalysis), biological (e.g., post-translational enzymatic modification and genetic code reprogramming), and supramolecular (e.g., mechanically interlocked, metal-directed folding and self-assembly via noncovalent interactions) macrocyclization strategies developed in recent decades. In this tutorial review, diverse state-of-the-art macrocyclization methodologies and techniques for peptides and peptidomimetics are surveyed and discussed, with insights into their practical advantages and intrinsic limitations. Finally, the synthetic-technical aspects, current unresolved challenges, and outlook of this field are discussed.

The unique features of metal-organic frameworks (MOFs) such as biodegradability, reduced toxicity and high surface area offer the possibility of developing smart nanosystems for biomedical applications through the simultaneous functionalization of their structure with biologically relevant ligands and the loading of biologically active cargos, ranging from small drugs to large biomacromolecules, into their pores. Aiming to develop efficient, naturally inspired biocompatible systems, recent research has combined organic and materials chemistry to design innovative composites that exploit carbohydrate chemistry for the functionalization and structural modification of MOFs. Scientific investigation in the field has seen a significant rise in the past five years, and it is becoming crucial to acknowledge both the limits and benefits of this approach for future investigation. In this review, the latest research results merging carbohydrates and MOFs are discussed, with a particular emphasis on the advances in the field and the remaining challenges, including addressing sustainability and real-case applicability.

A robust deamidation quantification method, called QuanDA, was developed to quantify the spontaneous nonenzymatic deamidation of peptides based on the isotopic distribution change of peptides in matrix-assisted laser desorption ionization (MALDI) mass spectra and non-negative least squares calculation. The predictive model of QuanDA using theoretical spectra of pure un-deamidated and deamidated peptides for a series of simulated partial deamidated peptides is satisfying, with a coefficient of determination (R²) and root mean squared error (RMSE) of 0.9914 and 0.03356, respectively. It was applicable in cases where there is a lack of reference standards of un-deamidated and deamidated peptides. The only requirements were the chemical formulae of un-deamidated and deamidated peptides for isotopic pattern calculation. QuanDA provided a rapid, low-cost and easily accessible method for deamidation analysis in therapeutic drugs.

A novel fluorescent probe, carbon dots/gold nanoclusters (CDs/AuNCs), was prepared for ratiometric and colorimetric detection of Pb²⁺ and Hg²⁺ simultaneously. The as-prepared probe exhibited two distinct emission peaks at 445 nm and 610 nm. During the detection process, Pb²⁺ could quench blue fluorescence due to the formation of the CDs-Pb²⁺ complex and does not affect orange fluorescence. Conversely, Hg²⁺ could quench the orange fluorescence greatly due to the Hg²⁺-Au⁺ metallophilic interaction and keep blue fluorescence unaffected. Accordingly, ratiometric fluorescence sensing approaches of Pb²⁺ and Hg²⁺ are achieved and dramatic color changes from pink to orange/blue can be observed under UV illumination upon the addition of Pb²⁺/Hg²⁺. Furthermore, good linear relationships between the fluorescence intensity ratio (I₆₁₀/I₄₄₅) and Pb²⁺/Hg²⁺ concentration were demonstrated in ranges of 0-130 nM for Pb²⁺ and 0 to 280 nM for Hg²⁺, with detection limits of 6.5 nM for Pb²⁺ and 3.7 nM for Hg²⁺, respectively. The probe showed excellent selectivity and the mutual interference problem of coexistence of Pb²⁺ and Hg²⁺ could be effectively solved by introducing masking agents. In addition, the application of CDs/AuNCs proved successful in detecting Pb²⁺ and Hg²⁺ in actual water samples, yielding satisfactory recovery rates. These results indicated that the probe provides a new approach for visualizing and semi-quantitatively detecting Pb²⁺ and Hg²⁺, making it highly promising for monitoring environmental water samples.

The presence of excessive nitrate in environmental and drinking water even at low levels can pose both environmental and health hazards. Because of this, various methods for its removal have been investigated. Essential to conducting such research is a method to reliably quantify nitrate in relevant matrices. However, current approaches have drawbacks related to cost, analysis time or health hazards. This study evaluates a UV spectroscopy-based method for nitrate determination, suitable for quantifying low nitrate concentrations in the presence of bicarbonate, sulfate, chloride and phosphate. The limits of detection and quantification were found to be 0.003 ppm N and 0.0077 ppm N respectively, lower than that observed in the ion chromatography method it was compared to. Additionally, a calibration curve created with 11 standards ranging from 0 to 2.5 ppm N demonstrated an exceptionally strong correlation, with an R² value greater than 0.9999. This method is developed with a focus on accessibility and speed, minimising hazards and waste generation for reduced environmental footprint. The effects of contaminants introduced through the use of commercial laboratory consumables are also discussed.

Pru p 3, a member of the lipid transfer protein family, is considered a major allergen from peach as it often induces serious allergic reactions in peach-allergic individuals. The high resistance of Pru p 3 to processing treatments and to digestion or enzymatic hydrolysis is probably the cause of the severity of this fruit allergy. The aim of this study was to determine the effect of treatment with a large number of proteases from different origins (vegetal, animal and microbial) on the degradation and allergenicity of Pru p 3. To perform this study, Pru p 3 was previously isolated using cation exchange chromatography and ultrafiltration, and the purified protein was incubated with proteases under different conditions. The results showed that only two of the fifteen proteases assayed were able to efficiently degrade the protein at acidic pH, as determined by SDS-PAGE. These two commercial acid proteases, derived from Aspergillus niger, decreased by more than 95% the immunoreactivity of Pru p 3 by ELISA using specific rabbit IgG, giving peptides lower than 3.2 kDa as determined by MALDI-TOF mass spectrometry. The hydrolysates obtained showed a greater than 70% decrease in reactivity of IgE compared to untreated Pru p 3 using three pools of sera from peach allergic individuals. Furthermore, when hydrolysates were tested by the prick test, in more than 90% of peach-allergic patients the average size of the wheal significantly decreased by between 72% and 85%. The results suggest that the acid protease from Aspergillus niger could be used to obtain novel hypoallergenic products more tolerable for peach-sensitive individuals.

Memristors are crucial in computing due to their potential for miniaturization, energy efficiency, and rapid switching, making them particularly suited for advanced applications such as neuromorphic computing and in-memory operations. However, these tasks often require different operational modes-volatile or nonvolatile. This study introduces a forming-free Ag/FeO_x/FeWO_x/Pt nanocomposite memristor capable of both operational modes, achieved through compliance current (CC) adjustment and structural engineering. Volatile switching occurs at low CC levels (<500 μA), transitioning to nonvolatile at higher levels (mA). Operating at extremely low voltages (<0.2 V), this memristor exhibits excellent uniformity, data retention, and multilevel switching, making it highly suitable for high-density data storage. The memristor successfully mimics fundamental biological synapse functions, exhibiting potentiation, depression, and spike-rate dependent plasticity (SRDP). It effectively emulates transitions from short-term memory (STM) to long-term memory (LTM) by varying pulse characteristics. Leveraging its volatile switching and STM features, the memristor proves ideal for reservoir computing (RC), where it can emulate dynamic reservoirs for sequence data classification. A physical RC system, implemented using digits 0 to 9, achieved a recognition rate of 93.4% in off-chip training with a deep neural network (DNN), confirming the memristor's effectiveness. Overall, the dual-mode switching capability of the Ag/FeO_x/FeWO_x/Pt memristor enhances its potential for AI applications, particularly in temporal and sequential data processing.

For the first time, the photochemical behavior of aryl-substituted 2,3-dihydropyrazine 1,4-dioxides was investigated. A common feature of all observed photoprocesses is the conversion of nitrone moieties into an oxaziridine ring to give substituted bi- or polycyclic systems. It was shown that the direction of the reaction depends on the irradiation wavelength and the employed solvent. For instance, the use of 365 nm UV light leads to the cyclization of both nitrone moieties. In contrast, visible-light irradiation (450 nm) allows one to regiospecifically utilize an aldonitrone unit to form 7-oxa-1,4-diazabicyclo[4.1.0]hept-4-ene 4-oxide derivatives. Generally, the oxaziridine ring possesses high reactivity and can be transformed in situ by various reagents. The molecular and crystal structures of the representatives of both bicyclic systems were solved for the first time with X-ray diffraction analysis.