Bioengineering & Translational Medicine最新文献

The tumor microenvironment (TME) is critical for cancer initiation, growth, metastasis, and therapeutic resistance. The extracellular matrix (ECM) is a significant tumor component that serves various functions, including mechanical support, TME regulation, and signal molecule generation. The quantity and cross-linking status of ECM components are crucial factors in tumor development, as they determine tissue stiffness and the interaction between stiff TME and cancer cells, resulting in aberrant mechanotransduction, proliferation, migration, invasion, angiogenesis, immune evasion, and treatment resistance. Therefore, broad knowledge of ECM dysregulation in the TME might aid in developing innovative cancer therapies. This review summarized the available information on major ECM components, their functions, factors that increase and decrease matrix stiffness, and related signaling pathways that interplay between cancer cells and the ECM in TME. Moreover, mechanotransduction alters during tumorogenesis, and current drug therapy based on ECM as targets, as well as future efforts in ECM and cancer, are also discussed.

Glioblastoma (GBM) is the most common primary malignant brain tumor diagnosed in adults, carrying with it an extremely poor prognosis and limited options for effective treatment. Various cell therapies have emerged as promising candidates for GBM treatment but fail in the clinic due to poor tumor trafficking, poor transplantation efficiency, and high systemic toxicity. In this study, we design, characterize, and test a 3D-printed cell delivery platform that can enhance the survival of therapeutic cells implanted in the GBM resection cavity. Using continuous liquid interface production (CLIP) to generate a biocompatible 3D hydrogel, we demonstrate that we can effectively seed neural stem cells (NSCs) onto the surface of the hydrogel, and that the cells can proliferate to high densities when cultured for 14 days in vitro. We show that NSCs seeded on CLIP scaffolds persist longer than freely injected cells in vivo, proliferating to 20% higher than their original density in 6 days after implantation. Finally, we demonstrate that therapeutic fibroblasts seeded on CLIP more effectively suppress tumor growth and extend survival in a mouse model of LN229 GBM resection compared to the scaffold or therapeutic cells alone. These promising results demonstrate the potential to leverage CLIP to design hydrogels with various features to control the delivery of different types of cell therapies. Future work will include a more thorough evaluation of the immunological response to the material and improvement of the printing resolution for biocompatible aqueous resins.

Tissue engineering has emerged as a promising avenue for reconstructive urology, though only a limited number of tissue-engineered urethral constructs have advanced to clinical testing. Presently, there exists a dearth of agreement regarding the most promising constructs deserving of implementation in clinical practice. The objective of this review was to provide a comprehensive analysis of preclinical trials findings of a tissue-engineered urethra and to identify the most promising constructs for future translation into clinical practice. A systematic search of the Pubmed, Scopus, and PMC databases was conducted in accordance with the PRISMA statement. Manuscripts published in English between 2015 and 2022, reporting on the methodology for creating a tissue-engineered urethra, assessing the regenerative potential of the scaffold in a male animal model, and evaluating the clinical and histological outcomes of treatment, were included. A total of 48 manuscripts met the inclusion criteria, with 12 being eligible for meta-analysis. Meta-analysis revealed no significant benefit of any matrix type in terms of complication rates. However, acellular matrices demonstrated significant advantage over cellular matrices in case of no postoperative stricture formation (odds ratio = 0.06 [95% CI 0.01; 0.23], p < 0.01). Among all subgroups (animal models and scaffold types), the usage of acellular matrices resulted in advantageous effects. The meta-regression analysis did not show a significant impact of defect length (β1 = −0.02 [−0.28; 0.23], p = 0.86). We found that decellularized materials may carry less relevance for urethral reconstruction due to unfavorable preclinical outcomes. Natural polymers, used independently or with synthetic materials, resulted in better postoperative outcomes in animals compared to purely synthetic constructs. Acellular scaffolds showed promising outcomes, matching or exceeding cellular constructs. However, more studies are needed to confirm their clinical effectiveness.

Lymph node (LN)-resident dendritic cells (DCs) are a promising target for vaccination given their professional antigen-presenting capabilities and proximity to a high concentration of immune cells. Direct intra-LN injection has been shown to greatly enhance the immune response to vaccine antigens compared to traditional intramuscular injection, but it is infeasible to implement clinically in a vaccination campaign context. Employing the passive lymphatic flow of antigens to target LNs has been shown to increase total antigen uptake by DCs more than inflammatory adjuvants, which recruit peripheral DCs. Herein, we describe a novel vaccination platform in which two complementary multi-arm poly(ethylene glycol) (PEG) polymers—one covalently bound to the model antigen ovalbumin (OVA)—are injected subcutaneously into two distinct sites. These materials then drain to the same LN through different lymphatic vessels and, upon meeting in the LN, rapidly crosslink. This system improves OVA delivery to, and residence time within, the draining LN compared to all control groups. The crosslinking of the two PEG components also improves humoral immunity without the need for any pathogen-mimicking adjuvants. Further, we observed a significant increase in non-B/T lymphocytes in LNs cross-presenting the OVA peptide SIINFEKL on MHC I over a dose-matched control containing alum, the most common clinical adjuvant, as well as an increase in DC activation in the LN. These data suggest that this platform can be used to deliver antigens to LN-resident immune cells to produce a stronger humoral and cellular immune response over materials-matched controls without the use of traditional adjuvants.

Conventional chemotherapeutic agents are limited by their lack of targeting and penetration and their short retention time, and chemotherapy might induce an immune suppressive environment. Peptide self-assembly can result in a specific morphology, and the resulting morphological changes are stimuli responsive to the external environment, which is important for drug permeation and retention of encapsulated chemotherapeutic agents. In this study, a polypeptide (Pep1) containing the peptide sequences PLGLAG and RGD that is responsive to matrix metalloproteinase 2 (MMP-2) was successfully developed. Pep1 underwent a morphological transformation from a spherical structure to aggregates with a high aspect ratio in response to MMP-2 induction. This drug delivery system (DI/Pep1) can transport doxorubicin (DOX) and indomethacin (IND) simultaneously to target tumor cells for subsequent drug release while extending drug retention within tumor cells, which increases immunogenic cell death and facilitates the immunotherapeutic effect of CD4⁺ T cells. Ultimately, DI/Pep1 attenuated tumor-associated inflammation, enhanced the body's immune response, and inhibited breast cancer growth by combining the actions of DOX and IND. Our research offers an approach to hopefully enhance the effectiveness of cancer treatment.

Gestational diabetes mellitus (GDM) is a pregnancy disorder associated with short- and long-term adverse outcomes in both mothers and infants. The current clinical test of blood glucose levels late in the second trimester is inadequate for early detection of GDM. Here we show the utility of Raman spectroscopy (RS) for rapid and highly sensitive maternal metabolome screening for GDM in the first trimester. Key metabolites, including phospholipids, carbohydrates, and major amino acids, were identified with RS and validated with mass spectrometry, enabling insights into associated metabolic pathway enrichment. Using classical machine learning (ML) approaches, we showed the performance of the RS metabolic model (cross-validation AUC 0.97) surpassed that achieved with patients' clinical data alone (cross-validation AUC 0.59) or prior studies with single biomarkers. Further, we analyzed novel proteins and identified fetuin-A as a promising candidate for early GDM prediction. A correlation analysis showed a moderate to strong correlation between multiple metabolites and proteins, suggesting a combined protein-metabolic analysis integrated with ML would enable a powerful screening platform for first trimester diagnosis. Our study underscores RS metabolic profiling as a cost-effective tool that can be integrated into the current clinical workflow for accurate risk stratification of GDM and to improve both maternal and neonatal outcomes.

The hollow fiber membrane bundle is the functional component of artificial lungs, transferring oxygen to and carbon dioxide from the blood. It is also the primary location of blood clot formation and propagation in these devices. The geometric design of fiber bundles is defined by a narrow set of parameters that determine gas exchange efficiency and blood flow resistance, principally: fiber packing density, path length, and frontal area. These same parameters also affect thrombosis. This study investigated the effect of these parameters on clot formation using 3D printed flow chambers that mimic the geometry and blood flow patterns of fiber bundles. Hollow fibers were represented by an array of vertical micro-rods (380 μm diameter) arranged with three packing densities (40%, 50%, and 60%) and two path lengths (2 and 4 cm). Blood was pumped through these devices corresponding to three mean blood flow velocities (16, 20, and 25 cm/min). Results showed that (1) clot formation decreases dramatically with decreasing packing density and increasing blood flow velocity, (2) clot formation at the outlet of the fiber bundle enhances deposition upstream, and consequently (3) greater path length provides greater clot-free fiber surface area for gas exchange than a shorter path length. These results can help guide the design of less thrombogenic, more efficient artificial lung designs.

While surgical resection is a mainstay of cancer treatment, many tumors are unresectable due to stage, location, or comorbidities. Ablative therapies, which cause local destruction of tumors, are effective alternatives to surgical excision in several settings. Ethanol ablation is one such ablative treatment modality in which ethanol is directly injected into tumor nodules. Ethanol, however, tends to leak out of the tumor and into adjacent tissue structures, and its biodistribution is difficult to monitor in vivo. To address these challenges, this study presents a cutting-edge technology known as Light-Activatable Sustained-Exposure Ethanol Injection Technology (LASEIT). LASEIT comprises a three-part formulation: (1) ethanol, (2) benzoporphyrin derivative, which enables fluorescence-based tracking of drug distribution and the potential application of photodynamic therapy, and (3) ethyl cellulose, which forms a gel upon injection into tissue to facilitate drug retention. In vitro drug release studies showed that ethyl cellulose slowed the rate of release in LASEIT by 7×. Injections in liver tissues demonstrated a 6× improvement in volume distribution when using LASEIT compared to controls. In vivo experiments in a mouse pancreatic cancer xenograft model showed LASEIT exhibited significantly stronger average radiant efficiency than controls and persisted in tumors for up to 7 days compared to controls, which only persisted for less than 24 h. In summary, this study introduced LASEIT as a novel technology that enabled real-time fluorescence monitoring of drug distribution both ex vivo and in vivo. Further research exploring the efficacy of LASEIT is strongly warranted.

Cowpea mosaic virus (CPMV) has demonstrated superior immune stimulation and efficacy as an intratumoral immunotherapy, providing a strong argument for its clinical translation. One important consideration for any new drug candidate is the long-term stability of the drug and its formulation. Therefore, our lab has evaluated the physical stability and biological activity, that is, anti-tumor potency, of formulations of CPMV in buffer (with and without a sucrose preservative) in multiple temperature conditions ranging from ultralow freezers to a heated incubator over a period of 9 months. We found that non-refrigerated temperatures 37°C and room temperature quickly led to CPMV destabilization, as evidenced by significant protein and RNA degradation after just 1 week. Refrigerated storage at 4°C extended physical stability, though signs of particle breakage and RNA escape appeared after 6 and 9 months. CPMV stored in frozen conditions, including −20°C, −80°C, and liquid N₂, remained intact and matched the characteristics of fresh CPMV throughout the duration of the study. The biological activity was evaluated using a murine dermal melanoma model, and efficacy followed the observed trends in physical stability: CPMV stored in refrigerated and warmer conditions exhibited decreased anti-tumor efficacy compared to freshly prepared formulations. Meanwhile, frozen-stored CPMV performed similarly to freshly purified CPMV, resulting in reduced tumor growth and extended survival. Data, therefore, indicates that CPMV stored long-term in cold or frozen conditions remains stable and efficacious, providing additional support to advance this powerful plant virus to translation.

Heart valve replacement surgeries are performed on patients suffering from abnormal heart valve function. In these operations, the problematic tissue is replaced with mechanical valves or with bioprosthetics that are being developed. The thrombotic effect of mechanical valves, reflecting the need for lifelong use of anticoagulation drugs, and the short-lived nature of biological valves make these two types of valves problematic. In addition, they cannot adapt to the somatic growth of young patients. Although decellularized scaffolds have shown some promise, a successful translation has so far evaded. Although decellularized porcine xenografts have been extensively studied in the literature, they have several disadvantages, such as a propensity for calcification in the implant model, a risk of porcine endogenous retrovirus (PERV) infection, and a high xenoantigen density. As seen in clinical data, it is clear that there are biocompatibility problems in almost all studies. However, since decellularized sheep heart valves have not been tried in the clinic, a large data pool could not be established. This review compares and contrasts decellularized porcine and sheep xenografts for heart valve tissue engineering. It reveals that decellularized sheep heart valves can be an alternative to pigs in terms of biocompatibility. In addition, it highlights the potential advantages of bioinks derived from the decellularized extracellular matrix in 3D bioprinting technology, emphasizing that they can be a new alternative for the application. We also outline the future prospects of using sheep xenografts for heart valve tissue engineering.