Frontiers in Bioengineering and Biotechnology最新文献

Introduction: Diabetic nephropathy (DN) is characterized by progressive podocyte injury, yet actionable upstream regulators and precise targeted delivery strategies remain limited. This study investigated the role of poly (ADP-ribose) polymerase 1 (PARP1) in hyperglycemia-induced podocyte damage and developed a biomimetic targeted siRNA delivery system to silence PARP1.

Methods: Transcriptomic profiling was performed in MPC5 podocytes exposed to high glucose. Functional validation was conducted using the PARP1 inhibitor PJ-34 and PARP1 gene silencing in vitro and in a streptozotocin-induced type 1 diabetic mouse model. A PLGA-core nanoparticle system loaded with PARP1 siRNA and coated with red blood cell membrane (RBCm), further functionalized with the podocyte-targeting ligand BMS-α, was engineered and evaluated for targeting efficiency and therapeutic efficacy.

Results: PARP1 was significantly upregulated under high-glucose conditions and associated with activation of the TGFβ/Smads signaling pathway. Pharmacological inhibition and gene silencing of PARP1 attenuated pathway activation, restored autophagic flux, and reduced apoptosis, inflammation, and profibrotic responses in vitro, while alleviating glomerular injury in diabetic mice. The siPARP1-NPs@RBCm-BMS-α system demonstrated favorable physicochemical stability, effective siRNA encapsulation, enhanced podocyte targeting, and improved renal structure and function in vivo.

Discussion: These findings identify PARP1 as a key regulator of podocyte injury in DN via the TGFβ/Smads pathway and support the biomimetic receptor-relevant siRNA platform as a promising targeted therapeutic strategy for diabetic nephropathy.

Background: Peripheral nerve injuries often lead to painful neuroma formation and chronic neuropathic pain, and the optimal surgical strategy for prevention remains debated. Targeted muscle reinnervation (TMR), regenerative peripheral nerve interfaces (RPNI), and nerve-in-muscle implantation (NIM) are surgical techniques developed to mitigate neuroma-related pain, but their relative efficacy has not been compared systematically. This preclinical study compared TMR, NIM, and two RPNI variants in a rat tibial nerve transection model to identify which approach best reduces neuroma formation and pain.

Methods: Sprague-Dawley rats underwent right tibial nerve transection and were randomized into five groups: control (no repair), NIM, W-RPNI (wrapped RPNI), E-RPNI (embedded RPNI), or TMR. Behavioral outcomes including gait analysis (CatWalk), mechanical hypersensitivity (von Frey test), thermal hyperalgesia (Hargreaves test), and neuroma tenderness were assessed over 12 weeks. At week 12, distal nerve stumps and L4-L5 dorsal root ganglia (DRG) were harvested for histological evaluation, immunohistochemistry/immunofluorescence, and molecular analyses (qRT-PCR and Western blot) targeting pain- and inflammation-related biomarkers.

Results: By 12 weeks, TMR-treated rats showed the most robust improvements, including significantly longer stance duration, larger paw contact area, near-baseline withdrawal thresholds, and minimal neuroma tenderness, whereas untreated controls developed gross neuromas and persistent hypersensitivity. TMR also preserved organized nerve architecture with orderly axonal regeneration and minimal collagen I/III fibrosis at the stump. Molecular assays confirmed that TMR markedly attenuated nociceptive and inflammatory signaling, with TMR rats exhibiting the lowest expression of pain-related mediators (c-Fos, TRPA1, TRPV1, CGRP, NPY, BDNF) and pro-inflammatory/fibrotic markers (galectin, α-SMA, IL-1β, TNF-α, TGF-β) in nerve and DRG tissues. Conversely, the anti-inflammatory cytokine IL-10 and axonal ion pump subunits ATP1A2/ATP2B1 were significantly upregulated with TMR. Outcomes for the two RPNI groups were similar to each other and generally intermediate between TMR and control.

Conclusion: TMR was superior to RPNI variants and NIM in preventing neuroma formation and alleviating neuropathic pain in this animal model. These findings support TMR as a promising surgical strategy to mitigate post-amputation neuroma pain.

Anaerobic biodigesters play a crucial role in the sustainable development of rural areas, managing waste and generating renewable energy. This review evaluates the development and performance of the fixed dome, floating drum, and tubular biodigesters, viz, shows how design improvements and operational strategies impact their efficiency. The original design of these traditional models was found to be restricted by microbial instability caused by climate fluctuations and operational disturbances. In response, modern designs incorporated specific adaptations, such as thermal control and feedstock optimization. The fixed dome model demonstrated improved durability and performance with solar heating and self-mixing capabilities that increase methane production and volatile solids removal. In contrast, floating drum digesters, which are constantly limited by corrosion and inconsistent yields, have been developed to incorporate plastic protective layers, integrated mixing shafts, and in-situ purification to achieve better methane concentrations and improved system efficiency. Affordable and adaptable tubular digesters with modular expansion capabilities, incorporating trench burial and greenhouse enclosures, have been designed to enhance affordability and mitigate the effects of climate change. The modifications increase methane production, process stability, and energy recovery. Biodigester performance and efficiency are fundamentally driven by design. Accordingly, the future adoption of anaerobic biodigesters will depend on locally adaptable and affordable systems supported by practical maintenance frameworks, as well as community awareness and training. Overall, recent design innovations have enabled a shift from climate-sensitive traditional models toward more durable, efficient, and adaptable digesters capable of stabilizing methane yield under variable operating conditions.

Mild traumatic brain injury (mTBI), or concussion, is a prevalent public health issue that imposes a substantial economic and social burden on individuals and healthcare systems. Although mTBI is often attributed to brain deformation induced by angular acceleration of the head, its precise mechanisms, including the relationship between local deformations of the brain parenchyma or axonal fibers and clinical symptoms, have not yet been elucidated. Finite element (FE) models of the human brain have been widely used to estimate brain strain in various impact scenarios associated with mTBI. However, despite the possibility that mTBI-related neuropathological changes may involve disruptions of neural pathways connecting different brain regions, most existing models do not account for the architecture of axonal fibers at the anatomical tract level. This study proposes an advanced human brain FE model that explicitly incorporates axonal fiber tracts derived from a group-averaged tractography atlas. The tracts were embedded as a series of continuous beam elements into the solid elements of the brain parenchyma, enabling dynamic evaluation of axonal strain for each tract during head impacts. The model was validated against experimental data on brain deformation from postmortem human subject tests and exhibited comparable or superior correlation scores relative to existing models. Reconstruction simulations of eight real-world mTBI cases, including both vehicular- and sports-related impacts, were conducted using the developed model by comparing two axonal strain-based injury metrics across the cases. The results consistently showed higher injury metrics in specific tract, including the posterior thalamic radiation, body of the corpus callosum, frontal aslant tract, posterior corticostriatal tract, medial lemniscus, parietal corticopontine tract, and superior longitudinal fasciculus. Additionally, horizontal head rotation contributed more significantly to tract-level injury metrics than coronal or sagittal rotation. These findings provide new biomechanical insight into the relationship between mTBI and tract-level axonal damage. Furthermore, the proposed brain FE model may serve as a foundation for understanding mTBI mechanisms from a structural and functional connectome perspective, as a step toward improved mTBI prediction.

The implementation of textile electrodes offers the possibility of improving comfort and reducing the risk of allergic reactions of the measured subject, while also opening the door to non-medical devices for everyday life. The main objective of the experiment is to test and compare five conductive fabrics manufactured by Shieldex in terms of the quality of the measured electrocardiography (ECG) signals. For this experiment, 3 electrodes of each conductive material were made and tested on a sample of 20 volunteers. The electrodes were attached by an elastic band at the locations of selected standardized ECG leads, and Ag/AgCl electrodes were used as reference. Correlation coefficient (R), signal-to-noice ratio (SNR) and percentage root-mean-square deviation (PRD) applied to representative cardiac periods were used to evaluate the quality of the acquired data. Differences in the results of the evaluation parameters between the different positions were noted, and when the distribution of positions was neglected, it was discovered that the best results were obtained with Shieldex Silitex material and, on the contrary, the worst results were recorded with Shieldex Technik-tex P130 + B material. It was also found that the results were not significant between the materials and after visual inspection it can be concluded that all materials are suitable for ECG measurements.

Background and introduction: Efficiently harnessing CO₂ for the bioproduction of chemicals stands as an important way to mitigate CO₂ emissions and actively advance the achievement of carbon neutrality. Drawing inspiration from the natural Calvin-Benson-Bassham (CBB) cycle for CO₂ fixation, the heterologous introduction of phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) into microbial cell factories emerges as a highly promising method for fully harnessing CO₂ for bioproduction purposes.

Methods: In this study, we engineered the industrial glutamate-hyperproducing strain Corynebacterium glutamicum YPGlu001 by introducing a heterologous RuBisCO-PRK pathway. Two metabolic configurations were evaluated: a "replacement" strategy, which blocked native glycolytic and pentose phosphate pathway (PPP) fluxes (via Δgap, ΔgapX, Δpgk, and Δzwf) to force carbon through the CBB shunt; and a "complementation" strategy, where the CO₂-fixation pathway supplemented the native central metabolism. Pathway performance was optimized through promoter engineering (P_tac, P_H30, P_fba, P_groES) and adaptive laboratory evolution (ALE) under increasing CO₂ stress.

Results: Comparative analysis revealed that the "replacement" strategy severely impaired cell growth and glutamate synthesis, with ALE failing to restore the desired production levels. In contrast, the "complementation" strategy significantly enhanced metabolic performance. The optimized strain GluE014 exhibited superior carbon-to-product conversion, achieving a glutamate titer of 196.78 g/L in a 5 L fed-batch fermenter within 30 h. This represents a 13.94% increase in titer and an 11.55% improvement in glucose-based yield compared to the parental strain. Furthermore, the engineered strain demonstrated improved carbon economy, reducing glucose consumption by 5.24% while maintaining high productivity.

Conclusion: This work demonstrates that "complementing" native metabolism with a CO₂-fixation shunt is more effective than "replacing" essential pathways in industrial C. glutamicum. By successfully integrating heterologous CO₂ assimilation with robust industrial fermentation, this study provides a scalable and efficient blueprint for developing next-generation, carbon-negative microbial cell factories.

[This corrects the article DOI: 10.3389/fbioe.2025.1621418.].

Acetylcholinesterase (AChE) is a crucial hydrolytic enzyme in the central nervous system, responsible for the rapid degradation of the neurotransmitter acetylcholine (ACh) in the synaptic cleft, thereby maintaining the balance between neuronal excitation and inhibition. AChE is not only the primary target of neurotoxic agents and organophosphorus pesticides but its aberrant activity is also closely associated with various neurodegenerative diseases such as Alzheimer's disease (AD) and myasthenia gravis. The efficient and rapid discovery and screening of AChE inhibitors hold urgent and significant value for chemical toxin detection, toxicological research, and drug development for neurodegenerative diseases. Addressing the limitations of existing methods, such as low biocompatibility, low detection throughput, relative operational complexity, and high cost, this study innovatively utilizes a genetically encoded biosensor to construct a stable cell line co-expressing the ACh probe and AChE, establishing a novel high-throughput screening method for AChE inhibitors. The results demonstrate that this method achieved to detect AChE inhibitors at micromole level. This method eliminates the need for purified enzymes and toxic chemical reagents (e.g., DTNB in Ellman's assay), significantly reduces cost (by approximately two orders of magnitude), and offers a simplified, rapid, and high-throughput compatible workflow for applications in neurotoxin detection and neurotherapeutic drug discovery.

Ureteral stent placement is a commonly executed clinical intervention for the treatment of upper urinary tract diseases. However, conventional non-degradable stents necessitate secondary extraction and are associated with complications such as infections, stone formation, and irritative symptoms when left indwelling for extended durations. To mitigate these risks, we introduce a novel three-layer gradient degradable ureteral stent (PTGGDG) developed from copolymers of TMC and GA [P(TMC-co-GA), abbreviated as PTG] using a multilayer impregnation technique. The structural design comprises PTG6040, PTG5050, and PTG4060 layers arranged from the inner layer to the outer layer. The present study systematically explored the relationship between the molecular chemical structure of the stent and its macroscale performance under varying proportions. The findings of this study demonstrate that PTGGDG exhibits a tensile strength of 34.69 MPa, coupled with exceptional flexibility, thus substantiating its compliance with the stringent mechanical support criteria stipulated for ureteral stents. The degradation behavior of PTG ureteral stents was rigorously assessed in artificial urine (AU) and aspergillus oryzae lipase-PBS (AP) environments. By modulating the PGA content in the formulation, the stents exhibited controllable degradation rates and maintained satisfactory morphological stability. In the present study, the stent was found to undergo predominantly hydrolytic degradation driven by GA, with the gradient structure extending functional support and minimising abrupt structural failure over a degradation period of 42 days. The PTGGDG stent undergoes preferential degradation of the outer layer in the AU due to the rapid degradation of its PTG4060 component. The middle layer's PTG5050 plays a buffering role in this process. The inner layer's PTG6040 degrades more slowly, ensuring a smooth lumen flow and allowing the degradation fragments to be discharged with artificial urine. This prevents obstruction of the ureteral stent fragments. In AP, the predominant form of erosion was enzymatic, driven by TMC, resulting in a degradation timeframe of 13 days. This gradient design is promising as it maintains urinary luminal patency while facilitating degradation in accordance with clinical requirements, thereby keeping urine pH within physiological ranges and providing insights for the optimization of materials and structural integrity in degradable ureteral stents.

Large bone defects remain a major clinical challenge and often require load-bearing implants for reconstruction. Titanium alloys are widely used for bone defect repair because of their favorable mechanical properties and biocompatibility; however, their high elastic modulus and limited bioactivity can cause stress shielding and insufficient osseointegration. Porous architectures have therefore been introduced to tailor the elastic modulus and promote bone ingrowth. This review summarizes current clinical applications and unresolved challenges of porous titanium implants, and integrates recent preclinical evidence on manufacturing routes and key design parameters. We analyze how pore topology (periodic versus stochastic architectures), pore size, porosity, strut diameter, and multiscale designs affect osseointegration. Overall, the review provides design-oriented insights and highlights prospects and challenges for future preclinical and clinical research to improve the osseointegration of porous titanium implants.