Bioengineering & Translational Medicine最新文献

A major concern of conventional photodynamic therapy is its non-specific toxicity due to off-site drug accumulation. Micelles tend to localize the drug to the tumor site. However, rapid drug release at high concentrations from the micelles to kill the cancer cells remains a formidable task. In this manuscript, we have introduced the 2-nitrobenzyl (2NB)-moiety as the linker between mPEG and the photosensitizer, chlorin e6 (Ce6), to prepare the conjugate, mPEG(2-nitrobenzyl)Ce6. We envision that 2NB as a linker between hydrophobic, Ce6, and hydrophilic mPEG would be more effective in releasing Ce6 by disassembling PEGylated 2-nitrobenzyl chlorin e6 (mPNCe6) Ms. Characterization through Fourier transform infrared spectroscopy and ¹H, ¹³C nuclear magnetic resonance spectra validated the successful synthesis of the conjugate. By conjugating Ce6 into the hydrophobic core of the micelles, exposure to near-infrared light significantly hastened the dissociation of the micelles, facilitating a controlled and rapid release of Ce6's hydrophobic components within the micelles. A cellular uptake study was performed, showing that Ce6 conjugation has improved the uptake of Ce6. The cell viability assay revealed that the formulation had shown concentration-dependent cytotoxicity upon laser irradiation. mPNCe6 group with laser irradiation has generated abundant reactive oxygen species (ROS) inside cells and exhibited green solid fluorescence, indicating the efficient delivery of Ce6 by mPNCe6 micelles and its excellent ROS generation ability inside cells upon laser irradiation. Further, in vivo studies on MOC2 tumor-bearing mice demonstrate reduced tumor growth, lung metastasis, and drug accumulation in the tumor region. The developed nanomedicine could be a potential treatment strategy for oral cancer, minimizing the occurrence of lung metastasis.

The homeostasis of branched-chain amino acids (BCAAs) plays a crucial role in maintaining health, and the accumulation of BCAAs can lead to various diseases. Therefore, exogenous degradation or conversion of excessive BCAAs may help alleviate diseases caused by BCAA accumulation, such as maple syrup urine disease. This study utilized synthetic biology approaches to engineer two strains for efficient BCAA catabolism successfully—ECN-Deg and ECN-Tra—by integrating specific metabolic pathways into the chassis strain, Escherichia coli Nissle 1917 (ECN). ECN-Deg integrates a metabolic module for BCAA degradation, while ECN-Tra integrates a metabolic module for BCAA transformation. Both engineered strains demonstrate efficient BCAA catabolism in vitro and in vivo. In a high-BCAA mouse model, ECN-Deg and ECN-Tra alleviated liver and ileal damage caused by excessive BCAAs and reduced systemic inflammation levels. Furthermore, ECN-Deg and ECN-Tra were able to modulate the gut microbiota, increasing the richness of Akkermansia muciniphila and Mucispirillum schaedleri, which are associated with health benefits. Additionally, they reduced the richness of the pathogenic bacterium Streptococcus pasteurianus. Thus, this study lays the foundation for the development of probiotics for the treatment of BCAAs metabolic disorders and BCAAs-related chronic diseases.

Atherosclerosis (AS) is a complex cardiovascular disease characterized by endothelial dysfunction, dyslipidemia, and immune-inflammatory responses, leading to arterial plaque formation and potentially fatal complications such as myocardial infarction and stroke. Traditional treatments, such as statins, often pose challenges due to their side effects and limited efficacy. In this study, we explore a novel therapeutic approach utilizing engineered endothelial cells (ECs) targeting probiotic extracellular vesicles loaded with dihydrotanshinone I (DHT) (EC-BEVs^DHT), a bioactive compound derived from Danshen (Salvia miltiorrhiza Bunge). With the characterization of EC-BEVs^DHT by transmission electron microscope and nanoparticle tracking analysis, EC-BEVs^DHT exhibited typical spherical morphology and particle size distribution. High-performance liquid chromatography coupled with tandem mass spectrometric confirmed the expression of the ECs-targeting peptide VSSSTPR in EC-BEVs^DHT and EC-BEVs^DHT. We further investigated the anti-atherosclerotic effects and molecular mechanisms of EC-BEVs^DHT on human umbilical vein endothelial cells (HUVECs) and Apolipoprotein E-deficient (ApoE^−/−) C57BL/6J mice. We found that EC-BEVs^DHT attenuated oxidized low-density lipoprotein induced HUVECs injury in vitro and decreased AS in ApoE^−/− mice in vivo. Our findings suggest that EC-BEVs^DHT hold promise as a safe and effective therapeutic strategy for AS, offering potential advantages over traditional treatments.

Peripheral nerves are vulnerable to trauma, pressure, and surgical injuries, complicating the regeneration process. While the autograft remains the gold standard for recovery, limitations such as tissue availability and donor site morbidities have led to the exploration of the allografts. However, conventional detergent-based decellularization methods in preparing allografts often cause residual toxicity and damage to the extracellular matrix (ECM). To address such challenges, we propose a sodium hydroxide (NaOH)-based decellularization technique that minimizes harmful residues. Our findings demonstrate that this method effectively removes inflammatory materials while preserving the ECM components and structures, and significantly reduces lipid and detergent residues. In vitro studies confirmed that the human nerves processed with the NaOH-based decellularization technique show low cytotoxicity and support elevated cell viability and proliferation. We further compared the performance of NaOH-based decellularized human nerves with that of autografts through an in vivo rabbit sciatic nerve defect model. NaOH-based decellularized nerves showed functional recovery comparable to autografts. Our findings demonstrate structural regeneration through neurofilament and laminin expression, indicating recovery levels similar to those of autografts. This study highlights that decellularized human nerve grafts through the NaOH-based protocol can promote nerve regeneration comparable to autografts, which can offer a safe and effective option for the treatment and reconstruction of peripheral nerve defects.

Electroporation-mediated delivery offers a promising alternative to carrier-based nucleic acid delivery methods for vaccination and therapeutic applications. Carrier-based systems like lipid nanoparticles and viral vectors often suffer from poor in vivo stability, immunogenicity, toxicity, and off-target effects. To overcome the high cost, bulkiness, lack of portability, and painful administration of traditional electroporators, we developed the RotoPatch family of small, low-cost, hand-held piezoelectric electroporators that use microneedle electrodes for intradermal delivery of nucleic acids. Notably, these RotoPatch devices use a single rotary motion to administer multiple electroporation pulses through microneedle electrodes, that localize the electric field to the upper layers of the skin. In animals, RotoPatch facilitated greater intracellular uptake of firefly luciferase-encoded mRNA in mice and green fluorescent protein-encoded plasmid DNA in rats, as confirmed by bioluminescence and fluorescence imaging, respectively. RotoPatch produced similar in vivo expression as electroporation using a manually actuated, multi-pulse piezoelectric electroporator (ePatch) and a battery-powered, multi-pulse electroporator (eIgniter). These findings highlight the potential of multi-pulse piezoelectric microneedle electroporation for intradermal nucleic acid delivery as a platform for gene therapy and vaccination.

Contraceptive methods based on intrauterine devices (IUD) typically result in women being constantly exposed to either hormones or copper ions. Although it is well known that the pH in vaginal fluids increases from around 3.5 to 7 during intercourse, pH-responsive materials have yet to be explored for controlling the local release of contraceptive agents. Here, we describe the design of an open-source smart IUD able to modulate copper ion release on demand thanks to the integration of pH-sensitive biopolymer-based hydrogels. Both anionic and cationic hydrogels with different release strategies were investigated. In anionic gels, an increase in pH promotes an increase in the diffusion coefficient; while in cationic gels, an alkaline environment results in shrinking, exposing part of the copper wire. Computational simulations were used to verify that gel thickness was appropriate for minimal copper ion leaching at low pH and effective dose release at higher pH. A thin gel coating was integrated into a commercial IUD using a custom 3D printed mold. Copper ion release was investigated at different time points in acid and basic solutions. The results show that both anionic and cationic gels can be used to engineer smart and safer IUDs.

The house dust mite Dermatophagoides pteronyssinus produces major allergens (Der p 1, Der p 2, and Der p 23) that require precise IgE detection for clinical diagnosis. We developed a multiplex digital ELISA using fluorescence-encoded micromagnetic beads (532 nm/638 nm dual-wavelength system) coupled with microfluidics to simultaneously quantify serum IgE against these components, with comprehensive evaluation against the clinical standard UniCAP system. The 532 nm channel measured allergen-specific signals via average brightness increase (ABMB) of enzymatically amplified fluorescence, while 638 nm enabled spectral bead differentiation. Comparative evaluation with UniCAP showed the improved digital ELISA achieved uniform 75.0% sensitivity but variable specificity (42.9%–54.5%) across allergens at the 15.8% ABMB threshold. Sample classification results (Der p 1: 9 positive/6 negative; Der p 2: 7/8; Der p 23: 7/8) demonstrated suboptimal positive predictive values (33.3%–60.0%) versus more favorable negative predictive values (60.0%–85.7%), with likelihood ratios (LR+: 1.31–1.65) and Cohen's κ (0.12–0.25) suggesting limited diagnostic reliability. The automated platform offered 60% reduced sample volume (20 μL vs. 50 μL), multiplex capability, and maintained sensitivity for low-titer samples, representing an efficient screening solution pending specificity enhancement.

Ulcerative colitis (UC) remains a significant therapeutic challenge due to its complex pathogenesis involving oxidative stress, immune dysregulation, and gut microbiota dysbiosis. Melanin, a natural biopolymer with robust anti-inflammatory and antioxidant properties, presents a promising treatment avenue for UC. Probiotics, particularly Escherichia coli Nissle 1917 (EcN), have gained recognition for their role in restoring gut homeostasis. In this study, we genetically engineered EcN to overexpress tyrosinase (EcN-T), facilitating the biosynthesis of melanin specifically for UC treatment. The engineered probiotics demonstrated superior therapeutic efficacy compared to either melanin or EcN administered alone, highlighting a synergistic effect. EcN-T not only exhibited significant capabilities in scavenging reactive oxygen species and restoring gut microbiota but also possessed the characteristic of enhancing gut colonization time, thereby extending the dosing frequency. Moreover, EcN-T showcased novel mechanisms, such as the restoration of the intestinal mucosal barrier and the elevation of short-chain fatty acid levels. Additionally, EcN-T inhibited M1 macrophage polarization through Hypoxia-Inducible Factor 1-alpha (HIF-1α)dependent glycolytic reprogramming, underscoring its immunomodulatory potential. Collectively, these findings provide new insights into the therapeutic potential of EcN-T for UC treatment, offering a novel strategy that enhances treatment efficacy while potentially reducing side effects associated with conventional therapies.