bims-livmat 2025-06-22 papers

Fundam Res. 2025 May;5(3): 1327-1345

Engineered bacteria: Strategies and applications in cancer immunotherapy.

Shuhao Zhang, Rui Li, Yunxue Xu, Renfa Liu, Desheng Sun, Zhifei Dai.

Cancer therapy remains a critical medical challenge. Immunotherapy is an emerging approach to regulating the immune system to fight cancer and has shown therapeutic potential. Due to their immunogenicity, bacteria have been developed as drug-delivery vehicles in cancer immunotherapy. However, ensuring the safety and efficacy of this approach poses a considerable challenge. This paper comprehensively explains the fundamental processes and synthesis principles involved in immunotherapy utilizing engineered bacteria. Initially, we list common engineered strains and discuss that growth control through genetic mutation promises therapeutic safety. By considering the characteristics of the tumor microenvironment and the interaction of specific molecules, the precision targeting of tumors can be improved. Furthermore, we present a foundational paradigm for genetic circuit construction to achieve controlled gene activation and logical expression, directly determining drug synthesis and release. Finally, we review the immunogenicity, the expression of immunomodulatory factors, the delivery of immune checkpoint inhibitors, and the utilization of bacteria as tumor vaccines to stimulate the immune system and facilitate the efficacy of cancer immunotherapy.

Keywords: Drug delivery; Engineered bacteria; Genetic circuits; Immunotherapy; Synthetic biology; Tumor targeting

DOI: https://doi.org/10.1016/j.fmre.2024.11.001

Front Microbiol. 2025 ;16 1603671

Unlocking the potential of engineered microbes in immunotoxin-based cancer therapy.

Quan Wang, Rui Cao, Yuxing Xie, Zhuoyi Zhang, Xianguo Li, Yan Zhang, Haolin Luo, Hui Yao, Ping Xue, Shuai Ni.

Immunotoxins (ITs), as targeted cancer therapies, confront limitations including off-target effects, immunogenicity, and inadequate tumor penetration, hindering clinical translation. Advances in tumor microenvironment (TME) understanding and genetic engineering have enabled engineered microorganisms such as attenuated Salmonella, E. coli Nissle 1917, and modified eukaryotic platforms (e.g., yeast, microalgae) to colonize tumors and act as efficient hosts for IT production. By integrating ITs into these microbes and employing precise circuits (e.g., phage lysis systems, signal peptide fusions), controlled secretion of recombinant immunotoxins (RITs) can be achieved. Balanced-lethal systems further enhance plasmid stability for sustained therapeutic delivery. This review highlights strategies leveraging engineered microbes to amplify IT efficacy, exemplified by preclinical successes like Salmonella-delivered TGFα-PE38 and E. coli-expressed anti-PD-L1-PE38. However, challenges persist, including dynamic TME interactions, systemic infection risks, manufacturing complexities and regulatory uncertainties demand resolution. By synergizing microbial targeting with RIT, this approach offers transformative potential for cancer therapy, yet requires multidisciplinary innovation to address technical, safety, and regulatory barriers for clinical adoption.

Keywords: cancer therapy; circuits; engineered microbes; immunotoxin; tumor penetration

DOI: https://doi.org/10.3389/fmicb.2025.1603671

Microbiol Spectr. 2025 Jun 18. e0282824

Oral delivery of GLP-1 peptide using recombinant Lactobacillus gasseri for the treatment of type 2 diabetes mellitus.

Zhiqiang Ke, Qianqian Ma, Xiaonan Ye, Yan Jin, Yanlin Wang, Xinyuan Zhao, Zhengding Su.

Glucagon-like peptide-1 (GLP-1) is an effective therapeutic peptide for the treatment of type 2 diabetes mellitus (T2DM). Here, we constructed an effective probiotic-based oral GLP-1 delivery system by engineering the probiotic strain of Lactobacillus gasseri (LgsGPA) to secrete GLP-1 fusion peptide, which combines GLP-1 with protein transduction domain (PTD) and a serum albumin binding peptide (ABP), GLP-1-PTD-ABP (GPA). The supernatants of LgsGPA cultures significantly upregulated the expression of PDX-1 and stimulated insulin release in Min6 cells. Daily oral administration of LgsGPA in db/db mice significantly alleviated insulin resistance, hyperglycemia, and dyslipidemia. Simultaneously, the abundance of unclassified_f_Erysipelotrichaceae and Intestinimonas was significantly reduced in db/db mice, while the average abundance of Akkermansia increased in the SD rats. These findings demonstrate that the probiotic-based delivery system represents a versatile and effective strategy for the oral administration of therapeutic peptides. Collectively, our results highlight the potential of this probiotic-based approach as a promising therapeutic and preventive intervention for T2DM.IMPORTANCEIt is important to develop the oral delivery strategy for therapeutic peptides. Due to issues with patient adherence and the low oral bioavailability of current administration methods, researchers have been exploring oral delivery strategies for GLP-1 analogs for many years, including the use of advanced microbiome therapeutics (AMTs). AMTs offer the potential to use engineered microbes for innovative therapeutic applications, such as the oral delivery of GLP-1 analogs. Our approaches offer a general oral delivery strategy for therapeutic peptides. The probiotic-based approach represents a promising method for treating and preventing T2DM.

Keywords: GLP-1 analog; Lactobacillus gasseri; advanced microbiome delivery; glucagon-like peptide-1; gut microbiota; oral delivery; protein transduction domain; serum albumin binding peptide; type 2 diabetes mellitus

DOI: https://doi.org/10.1128/spectrum.02828-24

J Agric Food Chem. 2025 Jun 19.

Lactic Acid Bacteria as Biofactories: Mechanistic Insights, Engineering Strategies, and Future Horizons for Heterologous Enzyme Expression.

Mati Ullah, Muhammad Naeem, Vivian Andoh, Muhammad Nadeem Khan, Jianda Han, Muhammad Rizwan, Nazar Hussain, Muhammad Saeed, Yong Chen, Huayou Chen.

Lactic acid bacteria (LAB) constitute a genetically heterogeneous group that is uniquely capable of converting soluble carbohydrates into lactic acid. Such LAB, with a long history of safe consumption in fermented foods, are considered food-grade microorganisms and are highly sought after for a variety of biotechnological applications. Due to their unique properties, LAB can be genetically engineered to produce industrially significant enzymes. LAB act as an expression host for these enzymes by combining already existing engineering systems with techniques such as CRISPR-Cas. This review outlines the progress achieved to date on genome manipulation methods for LAB engineering and future perspectives of genetic tools. These strategies contribute greatly to fully unleashing the potential of LAB, and we further elaborate on how genome editing tools can enhance the capacity of heterologous expression in LAB.

Keywords: CRISPR-Cas; enzymes; genome editing tools; lactic acid bacteria

DOI: https://doi.org/10.1021/acs.jafc.5c02311

ACS Omega. 2025 Jun 10. 10(22): 22679-22684

Evaluation of Probiotic Growth in Microenvironments Sculpted with Different Geometries.

Adriano J G Otuka, Jonathas Q R Moraes, Analú Barros de Oliveira, Eduardo J S Fonseca, Carla R Fontana, Cleber R Mendonca.

Probiotics benefit their host, potentially exerting microbial balance by stimulating the increase in beneficial bacteria in the intestinal environment. Some studies have shown that specific probiotic strains can alleviate symptoms of medical conditions such as Alzheimer's, reduce the action of carcinogenic agents, and control various biomarkers in women in the first half of pregnancy. In this context, it is important to determine the fundamental aspects of probiotic growth to develop more efficient delivery mechanisms in pharmaceuticals or foods. Miniaturized biomimetic environments can be useful for that purpose. In this way, we manufactured biocompatible three-dimensional platforms using two-photon absorption polymerization to study the growth of a pool of bacteria composed of Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus paracasei, and Bifidobacterium lactis, commonly used in commercial probiotics. The microstructures were fabricated using an acrylic resin employing 100 fs pulses from a Ti:sapphire laser. It was possible to manufacture biocompatible structures for probiotic development, demonstrating that microstructures serve as accelerators for bacterial growth. We evaluated the growth of bacteria in the environments over more than 36 h, giving all conditions for their development. Furthermore, it was observed that bacteria grow into structures with distinct geometries (circular or rectilinear) but tend to develop preferentially in protected environments with spacings on the order of 5 μm.

DOI: https://doi.org/10.1021/acsomega.4c11168

Front Bioeng Biotechnol. 2025 ;13 1545773

Multifunctional MeHA hydrogel for living materials delivery with enhanced cartilage regeneration.

Qunchao Chen, Lang Bai, Guoyang Wan, Yuefeng Hao, Xing Yang, Hongtao Zhang.

Particulated juvenile articular cartilage (PJAC) has emerged as a promising living material for articular defect treatment. However, the fragile nature of PJAC hinders its wide clinical application. Here, inspired by the chemical composition and hierarchical structure of natural cartilage, we developed a novel hydrogel carrier system for PJAC delivery. Our carrier system, MeHA@J@DM, utilized methacrylated hyaluronic acid (MeHA) to incorporate PJAC and coated it with a polymerized mixture of dopamine methacrylamide (DMA) and 2-methylacryloyloxyethyl phosphorylcholine (MPC), forming an adhesive lubricant, p(DMA-MPC). MeHA@J@DM exhibited excellent performance for PJAC protection with enhanced cell viability, bioactivity, and lubrication properties. We evaluated the effectiveness of MeHA@J@DM in cartilage cell migration, where juvenile cartilage showed greater efficiency and remodeling abilities. In vivo rabbit cartilage defect models demonstrated superior cartilage regeneration with the MeHA@J@DM hydrogel. Our findings suggest that MeHA@J@DM has translational potential for PJAC implantation to enhance cartilage regeneration and benefit patients with articular cartilage lesions.

Keywords: MeHA; cartilage repair; living materials; lubrication; particulated juvenile articular cartilage

DOI: https://doi.org/10.3389/fbioe.2025.1545773