bims-livmat 2025-07-20 papers

bims-livmat

Biomed News

on Living materials

Issue of 2025–07–20
fourteen papers selected by
Sara Trujillo Muñoz, Leibniz-Institut für Neue Materialien

Free-standing bacterial films reinforced with 2D Layered Double Hydroxide nanosheets: A Biohybrid Platform toward Engineered living materials.
Adaptation of the living therapeutic materials concept to the immune sensing of neutrophil granulocytes.
Genetically-programmed Hypervesiculation of Lactiplantibacillus plantarum Increases Production of Bacterial Extracellular Vesicles with Therapeutic Efficacy in a Preclinical Inflammatory Bowel Disease Model.
Metabolic Control for High-Efficiency Ectoine Synthesis in Engineered Escherichia coli.
Developing an In Vitro Model of Endotoxemia to Assess the Immunomodulatory Effects of Anti-Inflammatory Peptide-Secreting Living Therapeutics.
Gut-brain-immune interactions: exploring probiotics as a drug delivery platform for neurological disease.
Temporal gene regulation enables controlled expression of gas vesicles and preserves bacterial viability.
Engineered Probiotics for Colitis Therapy by Improving Intestinal Colonization and Scavenging ROS.
Bacteria into bloodstream caused by oral probiotics based on whole genome sequencing: A case report.
Microfluidic Fabrication of Hyaluronic Acid-Cysteine-Modified Chitosan Microspheres for CD44-Targeted Probiotic Delivery in Colitis Treatment.
Microencapsulation of Bacillus subtilis by spray-drying using starch hydrolysates with different dextrose equivalent values.
Probiotic properties of Lactiplantibacillus plantarum KS2020 with GABA producing ability.
Advances in optogenetically engineered bacteria in disease diagnosis and therapy.
Microalgae empower skeletal muscle via increased force production and viability.

Acta Biomater. 2025 Jul 15. pii: S1742-7061(25)00531-8. [Epub ahead of print]

Free-standing bacterial films reinforced with 2D Layered Double Hydroxide nanosheets: A Biohybrid Platform toward Engineered living materials.

Yanna Gurianov, Ilya Shlar, Elena Poverenov.

  The use of bacteria to fabricate materials has garnered significant attention in both fundamental and applied research. In this study, we introduce a method for producing bacteria-based materials utilizing the bacterial capacity to colonize 2D nanomaterials, which in turn provides additional robustness to the resulting bacterial film. Specifically, we demonstrate the fabrication of self-standing films based on a bacterium Bacillus pumilus reinforced with 2D nanosheets derived from Layered Double Hydroxides. The Live/Dead staining, followed by Confocal Laser Scanning Microscopy (CLSM), revealed an anisotropic distribution of live and dead bacteria within the mature biofilms leading to a stratified biofilm architecture. Scanning Electron Microscopy (SEM) confirmed the presence of endospores in the reinforced biofilm structure. Biological assays further supported this observation. Notably, simulated gastrointestinal passage experiments showed that the presented bacterial films provide significant protection to probiotic bacteria under harsh gastrointestinal conditions, suggesting their potential applicability in advanced delivery systems. The present study offers a useful approach for future innovations in bacteria-based material fabrication. STATEMENT OF SIGNIFICANCE: In this manuscript we present a sustainable approach for producing bacteria-based materials by harnessing the natural ability of bacteria to colonize 2D nanomaterials. Applying 2D LDH nanosheets contributed to endospores formation and structural robustness leading to the reinforced self-standing bacterial films. Moreover, the reinforced biofilms effectively protect probiotic bacteria under harsh gastrointestinal conditions. Our findings can contribute to the development of innovative bacteria-based living materials with potential applications in advanced delivery systems and regenerative medicine.

Keywords:  2D Nanomaterials; Biofilm engineering; Layered Double Hydroxides; Living materials; Probiotic Delivery

DOI:  https://doi.org/10.1016/j.actbio.2025.07.034
J Leukoc Biol. 2025 Jul 09. pii: qiaf086. [Epub ahead of print]117(7):

Adaptation of the living therapeutic materials concept to the immune sensing of neutrophil granulocytes.

Islam Mohamed, Kristin Burckhardt, Stefan Lohse.

  Neutrophils are innate immune cells that perpetually patrol the circulation and tissues. They sense and migrate toward invading microbes to initiate and orchestrate a robust immune response. Their highly reactive nature, driven by multiple and redundant receptor families recognizing bacterial components, makes them particularly sensitive to contaminants or nonsterile implants. This often leads to a neutrophil-driven foreign body reaction that shields the implant and triggers inflammation, collateral tissue damage, or even sepsis. This presents a significant challenge for living therapeutic materials, an innovative biomedical approach using genetically engineered bacteria encapsulated in natural or synthetic polymers. Since bacterial turnover inevitably releases pathogen-associated molecular patterns that activate neutrophils to mitigate or prevent a potent neutrophil response, living therapeutic material design strategies are required to protect the living therapeutic material from damage while maintaining its functionality. This review focuses on current strategies involving bacterial genetic engineering, immune-shielding materials and factors, and modified hydrogel-based systems to minimize immune recognition. Engineering the bacterial chassis to produce immune tolerance-inducing metabolites from commensals, modified pathogen-associated molecular patterns, and pathogen-associated molecular pattern-cleaving autolysins may enhance biocompatibility. A crucial aspect for clinical translation is robust biocontainment to prevent bacterial escape, ensuring living therapeutic material remains a safe and effective therapeutic platform. While the potential of the living therapeutic material concept lies in the development of tailored medicine specifically designed for a specific disease and enabling local, cost-effective, site- and stimulus-responsive treatment, balancing the neutrophil immune response remains an important milestone on the path to living therapeutic material for future biomedical applications.

Keywords:  engineered bacteria; gene modification; hydrogel; immune tolerance; neutrophils

DOI:  https://doi.org/10.1093/jleuko/qiaf086
bioRxiv. 2025 Jun 25. pii: 2025.06.20.660770. [Epub ahead of print]

Genetically-programmed Hypervesiculation of Lactiplantibacillus plantarum Increases Production of Bacterial Extracellular Vesicles with Therapeutic Efficacy in a Preclinical Inflammatory Bowel Disease Model.

Nicholas H Pirolli, Daniel Levy, Alyssa Schledwitz, Natalia Sampaio Moura, Talia J Solomon, Emily H Powsner, Raith Nowak, Zuzanna Mamczarz, Christopher J Bridgeman, Sulayman Khan, Laura Reus, Nidhi Anne, William E Bentley, Jean-Pierre Raufman, Steven M Jay.

Inflammatory bowel diseases (IBD) affect over 6 million people globally and current treatments achieve only 10-20% rates of durable disease remission. Bacterial extracellular vesicles (BEVs) from probiotic lactic acid bacteria (LAB) are a promising novel therapeutic with mechanisms holding potential to drive increased rates of durable disease remission, including immunomodulation and intestinal epithelial tissue repair. However, translation of these cell-secreted nanovesicles is limited by long standing biomanufacturing hurdles, especially low production yields due to low biogenesis rates from cells. Here, our goal was to identify a candidate probiotic LAB that produces BEVs effective in a preclinical mouse model of IBD, and then genetically engineer the LAB for at least 10-fold increased production yields of BEVs, thereby passing a critical production threshold. We identified Lactiplantibacillus plantarum as a candidate LAB producing BEVs effective in treating acute dextran sulfate sodium (DSS)-induced murine colitis, and with greater efficacy than BEVs from probiotic Escherichia coli Nissle 1917. We then genetically engineered a hypervesiculating L. plantarum strain by inducible expression of a peptidoglycan-modifying enzyme, resulting in a 66-fold increase in BEV productivity. Finally, we confirmed hypervesiculating L. plantarum BEVs were therapeutically effective in the acute DSS mouse model of colitis and found these BEVs were superior in reducing mucosal tissue damage compared to live L. plantarum cells. These findings demonstrate that BEVs from genetically engineered hypervesiculating strain of L. plantarum are a promising preclinical therapeutic candidate for IBD that overcomes historical biomanufacturing limitations of BEV therapeutics.

DOI: https://doi.org/10.1101/2025.06.20.660770
ACS Synth Biol. 2025 Jul 15.

Metabolic Control for High-Efficiency Ectoine Synthesis in Engineered Escherichia coli.

Zheng Lei, Xiangsong Chen, Lixia Yuan, Jinyong Wu, Jianming Yao.

  Ectoine is a pivotal natural osmoprotectant that functions as a compatible solute through osmoregulation, enabling microorganisms to thrive in extreme environments such as high salinity. To meet market demands, this study focuses on optimizing its production process. We initially engineered the ectABC gene cluster from Halomonas venusta via 5'-UTR modification, establishing a functional ectoine biosynthesis pathway in E. coli. Subsequent introduction of a rate-limiting enzyme EctB mutant (E407D) and aspartokinase mutant increased titer by 140%. To address lysine byproduct accumulation, an innovative molecular switch was employed to regulate lysA gene expression, achieving dynamic balance between cell growth and product synthesis. Further optimization through cofactor engineering yielded the final strain ECT31, which produced 164.6 g/L ectoine in a 100 L bioreactor within 117 h, the highest reported titer for E. coli-based ectoine production to date. The metabolic engineering strategy presented herein establishes a new pdigm for efficient biosynthesis of amino acid derivatives.

Keywords:  100 L bioreactor; Escherichia coli; ectoine; fed-batch fermentation; l-lysine; metabolic engineering

DOI:  https://doi.org/10.1021/acssynbio.5c00330
ACS Pharmacol Transl Sci. 2025 Jul 11. 8(7): 2180-2191

Developing an In Vitro Model of Endotoxemia to Assess the Immunomodulatory Effects of Anti-Inflammatory Peptide-Secreting Living Therapeutics.

Ketaki Deshpande, Varun Sai Tadimarri, Juliette Ramirez-Rangel, Shrikrishnan Sankaran, Sara Trujillo.

  Living therapeutics are attractive candidates to tackle the limitations of classically delivered therapeutic peptides, which are often poorly stable and require cost-intensive modifications. Their functional assessment is limited to animal experiments, which increase the complexity to evaluate the dynamic nature of these systems. Therefore, we developed an in vitro model of endotoxemia using macrophages to assess early-stage anti-inflammatory Living therapeutics. We refined the model based on three anti-inflammatory peptides (KCF-18, I6P7, and α-MSH) and identified suitable therapeutic concentrations and treatment durations. We applied the model to TF103, a probiotic engineered to secrete these peptides. The model revealed that Living therapeutics enhanced the effects of the peptides, requiring lower amounts of anti-inflammatory effects. This points to potential synergistic effects between peptides and bacteria. The model presented here allows the investigation of dynamic regimes, which could be useful in the development of complex systems such as the ones encountered in Living therapeutics.

Keywords:  Lactiplantibacillus plantarum; cytokines; immune response; probiotics; therapeutic peptides

DOI:  https://doi.org/10.1021/acsptsci.5c00216
Adv Drug Deliv Rev. 2025 Jul 09. pii: S0169-409X(25)00135-8. [Epub ahead of print] 115650

Gut-brain-immune interactions: exploring probiotics as a drug delivery platform for neurological disease.

Chinmayi R Gudi, Michael J Wannemuehler, Thomas J Mansell.

  The gut-brain-immune (GBI) axis, connecting gut microbes, neural tissue, and the cells of the immune system, plays a critical role in human health, particularly in relation to neurological diseases. Research in this field over the last few decades shows that disruptions in the microbiome have been linked to chronic inflammation, which may contribute to neurological conditions, including Parkinson's disease, Alzheimer's disease, and other mental health disorders. As we gain a greater understanding of the links between these systems, novel therapeutic strategies are being explored to treat disease by modulation of the GBI axis. One of the most promising approaches is the use of live biotherapeutics, such as engineered probiotics, as next-generation drug delivery systems. These live microorganisms can be designed to deliver specific therapeutic compounds to the gut and brain in order to modulate immune responses and reduce inflammation at the source. Probiotics and live biotherapeutics can offer a targeted approach to treating neurological diseases by influencing both the microbiome and immune system. In this review, we outline the research and mechanisms that have been implicated in GBI interactions and highlight the potential of these innovative therapies in treating neurological disorders, emphasizing their role in improving precision medicine through targeted, microbiome-based interventions.

Keywords:  Gut-brain immune axis; Live biotherapeutics; Neurological disease; Probiotic engineering; Targeted drug delivery

DOI:  https://doi.org/10.1016/j.addr.2025.115650
bioRxiv. 2025 Jun 20. pii: 2025.06.20.660610. [Epub ahead of print]

Temporal gene regulation enables controlled expression of gas vesicles and preserves bacterial viability.

Zongru Li, Sumin Jeong, George J Lu.

Gas vesicles (GVs) are genetically encodable, air-filled protein nanostructures that have rapidly emerged as a versatile platform for biomedical imaging, cell tracking, and therapeutic delivery. However, their heterologous expression in non-native hosts such as Escherichia coli can be challenging due to the complex assembly process, which often involves around ten different proteins and can lead to proteotoxic stress and impair cell growth. Here, we report the observation of a drop in cell density occurring 8 to 16 hours after GV induction in E. coli . To address these, we developed a dual-inducer transcriptional regulation system that enables orthogonal control of GV assembly factor proteins and the shell protein over a range of stoichiometries. Sequential induction in time, in which assembly factor expression is initiated before shell protein expression, restored normal bacterial growth and prevented lysis without compromising GV production. Further analysis revealed that varying the interval between the two induction steps affected both GV yields and cellular stress. By preserving cell integrity with GV expression, our approach enhances the utility of GV-expressing bacteria in applications that demand population-wide cellular stability and facilitates their broader application in biomedical engineering and synthetic biology.

DOI: https://doi.org/10.1101/2025.06.20.660610
ACS Macro Lett. 2025 Jul 17. 1075-1080

Engineered Probiotics for Colitis Therapy by Improving Intestinal Colonization and Scavenging ROS.

Siyuan Yuan, Xiaomei Dai, Yuqin Zou, Menglin Huang, Xue Yang, Feng Gao.

Probiotics hold significant promise for treating colitis, but their application remains challenging because of insufficient colonization and survival against colorectal oxidative stress. Herein, engineered probiotics were prepared to enhance probiotics' colonization and scavenge the overexpressed reaction oxygen species (ROS) at the site of colitis. First, primary amino groups on the Lactobacillus rhamnosus (LAB) surface were converted to free thiols by a simple one-step imidoester reaction. Then, we used thiol-initiated ring-opening cascade of dithiolanes to prepare a class of structurally dynamic microgels on the LAB surface (LAB-gel) by reacting alpha-lipoic acid (LA) and sodium thioctate (LANa). Finally, a lipid bilayer was coated on the surface of the LAB-gel to improve the stability of the microgel in gastric juice. Engineered probiotics survived an oxidative stress insult (100 μM H2O2) and were able to effectively colonize the colon. Furthermore, engineered probiotics could significantly uptake by macrophages and scavenge intracellular ROS. Engineered probiotics with enhanced colonization and ROS scavenging activity showed promising therapeutic effects on colitis.

DOI: https://doi.org/10.1021/acsmacrolett.5c00295
Medicine (Baltimore). 2025 Jul 11. 104(28): e43337

Bacteria into bloodstream caused by oral probiotics based on whole genome sequencing: A case report.

Tianqi Qi, Yingshi Wang, Yanhui Liu, Wenqiang Li, Shanshan Wu.

   RATIONALE: Bacillus licheniformis and Lactiplantibacillus plantarum are facultative anaerobes and gram-positive bacteria. They are commonly included in probiotic preparations and are administered orally in clinical practice to promote a balanced gut microbiota.
PATIENT CONCERNS: An 85-year-old man with irritable bowel syndrome and reflux esophagitis underwent distal pancreatectomy and was administered oral probiotics. Blood culture was positive for B. licheniformis and L. plantarum. We conducted whole-genome sequencing for homology analysis and pathogenicity prediction of the strains isolated from the patient's blood culture and oral probiotics.
DIAGNOSIS: The initial diagnosis was bacterial entry into the bloodstream resulting from the consumption of B. licheniformis and L. plantarum probiotic preparations.
INTERVENTIONS: The patient was treated with discontinuation of oral probiotics and timely administration of antibiotics.
OUTCOMES: Follow-up blood culture results after treatment were negative.
LESSONS: Probiotics are generally considered relatively safe but should be preceded by risk screening in vulnerable populations. Whole-genome sequencing revealed the potential risks of probiotic use through homology analysis and prediction of virulence factors and antibiotic resistance.

Keywords:  ; blood culture; probiotics; whole-genome sequencing

DOI:  https://doi.org/10.1097/MD.0000000000043337
ACS Appl Mater Interfaces. 2025 Jul 12.

Microfluidic Fabrication of Hyaluronic Acid-Cysteine-Modified Chitosan Microspheres for CD44-Targeted Probiotic Delivery in Colitis Treatment.

Fengzhi Qiao, Ya Luo, Peng Lei, Shaolei Wang, Zhi Duan, Hongchang Cui, Tongjie Liu, Huaxi Yi, Cristabelle De Souza, Guanhua Xuan, Xiangzhao Mao, Zhao Ma, Lanwei Zhang, Kai Lin.

  Probiotics play a crucial role in regulating intestinal immune homeostasis and supporting gut health; however, oral administration faces challenges such as nonspecific distribution and low efficacy. To achieve precise and efficient delivery, in this study, a targeted delivery system embedded probiotics to the colonic inflammatory site CD44 was constructed by covalently linking hyaluronic acid (HA) to cysteine-modified chitosan (CCH) using microfluidic technology. Two probiotic strains, Bifidobacterium bifidum FL-276.1 and Clostridium butyricum ATCC 19398, were encapsulated within the modified chitosan matrix to form probiotics@CCH microspheres (MSs), with an average diameter of approximately 276 μm. Based on the receptor-ligand binding mechanism of HA and CD44, combined with the intestinal mucosal adhesion properties conferred by cysteine-modified chitosan, the probiotics@CCH MSs exhibited a high capture rate for inflammatory Caco-2 cells and demonstrated prolonged retention and targeted localization in a DSS-induced colitis mouse model. Furthermore, probiotics@CCH MSs contributed to maintaining intestinal homeostasis by modulating gut microbiota composition, enhancing short-chain fatty acid production, and supporting the intestinal barrier integrity. The microfluidic-based delivery system facilitates the precise localization of probiotics within the intestine, providing a theoretical basis for enhancing probiotic applications in gut health management.

Keywords:  cysteine-modified chitosan; hyaluronic acid; inflammatory bowel disease; microfluidics; probiotic; targeted delivery

DOI:  https://doi.org/10.1021/acsami.5c10456
Int J Biol Macromol. 2025 Jul 15. pii: S0141-8130(25)06639-5. [Epub ahead of print] 146082

Microencapsulation of Bacillus subtilis by spray-drying using starch hydrolysates with different dextrose equivalent values.

Marina Momesso Lopes, Cristiane Sanchez Farinas, Manuel Martínez Bueno, Pedro J García-Moreno, Emilia M Guadix.

  Sustainable agricultural practices require innovative solutions to enhance productivity while reducing environmental impact. The use of plant growth-promoting microorganisms, such as Bacillus subtilis, as biofertilizers is a promising strategy. However, ensuring cell viability during storage and under field conditions remains a challenge. This study investigates the encapsulation of B. subtilis via spray-drying using starch hydrolysates with different dextrose equivalent (DE) values (DE-8, DE-18, and DE-38) as wall materials. Encapsulation efficiency was approximately 80 % for all formulations. The DE values influenced microcapsule morphology and cell release profiles, with higher DE materials producing smoother, smaller, and more homogeneous particles. The microcapsules effectively protected cells against high salinity and acidic pH stresses. Thermal stability was significantly improved with DE-18 and DE-38, maintaining over 95 % viability after 72 h at 50 °C. Under UV exposure, DE-18 demonstrated superior protection. Storage stability tests confirmed enhanced longevity for encapsulated cells compared to free bacteria, with higher DE microcapsules demonstrating better resilience to elevated temperatures. These findings highlight the potential of starch-based microencapsulation to improve biofertilizer performance, ensuring microbial survival and efficacy in diverse environmental conditions.

Keywords:  Bacillus; Carbohydrates; Encapsulation; Spray-drying; Starch hydrolysates

DOI:  https://doi.org/10.1016/j.ijbiomac.2025.146082
Food Sci Biotechnol. 2025 Aug;34(12): 2843-2853

Probiotic properties of Lactiplantibacillus plantarum KS2020 with GABA producing ability.

Min-Jeong Kwon, Yun-Ho Park, Joo-Hyeong Kim, Jeong-Min Lee, Syng-Ook Lee, Sam-Pin Lee.

  The probiotic properties and γ-aminobutyric acid (GABA)-producing ability of Lactiplantibacillus plantarum KS2020, isolated from dongchimi, were evaluated. Lb. plantarum KS2020 exhibited no resistance to antibiotics such as ampicillin, erythromycin, clindamycin, tetracycline, or chloramphenicol. It was also negative for hemolytic activity, cytotoxicity, and bile salt hydrolase activity, while producing negligible amounts of D-lactate, confirming its safety as a probiotic strain. The strain demonstrated strong tolerance to acid, gastric juice, and bile salts, thereby meeting the criteria for probiotics. In terms of GABA production, lactose was found to be the most effective sugar indicating 1.63% GABA production. However, GABA conversion did not occur in the absence of sugar or xylitol the strain could not utilize, highlighting the importance of carbon sources for GABA production. Therefore, Lb. plantarum KS2020 is confirmed as a safe probiotic with GABA-producing potential, suggesting its potential for developing novel probiotic-based functional foods.

Keywords:  Lactic acid bacteria; Lactiplantibacillus plantarum; Probiotic; γ-Aminobutyric acid

DOI:  https://doi.org/10.1007/s10068-025-01920-0
Biotechnol Adv. 2025 Jul 15. pii: S0734-9750(25)00131-4. [Epub ahead of print] 108645

Advances in optogenetically engineered bacteria in disease diagnosis and therapy.

Hui Wang, Zhijie Feng, Peiyuan Liu, Jing Liu, Duo Liu, Hanjie Wang.

  Optogenetic bacterial technology is a cutting-edge approach that combines optogenetics and microbiology, offering a transformative strategy for disease diagnosis and therapy. This synergistic merger transcends the limitations of traditional diagnostic and therapeutic methodologies in a highly controllable, accurate and non-invasive manner. In this review, we introduce the optogenetic systems developed for microbial engineering and summarize fundamental in vitro design principles underlying light-responsive signal transduction in bacteria, as well as the optogenetic regulation of bacterial behaviors. We address multidisciplinary solutions to the challenges in the in vivo applications of light-controlled bacteria, such as limited light excitation, suboptimal delivery and targeting, and difficulties in signal tracking and management. Furthermore, we comprehensively highlight the recent progress in photo-responsive bacteria for disease diagnosis and therapy, and discuss how to accelerate translational applications.

Keywords:  Disease diagnosis and therapy; Engineered bacteria; Multidisciplinary strategies; Optogenetics

DOI:  https://doi.org/10.1016/j.biotechadv.2025.108645
Sci Adv. 2025 Jul 18. 11(29): eadw5786

Microalgae empower skeletal muscle via increased force production and viability.

Xiang Wang, Claire Schirmer, Elena Totter, Simone Schuerle.

Engineered skeletal muscle holds potential for tissue engineering and biohybrid robotics applications. However, current strategies face challenges in enhancing force generation while maintaining stability and scalability of the muscle, largely due to insufficient oxygenation and limited nutrient delivery. In this study, we present an engineering approach to address these limitations by coculturing Chlamydomonas reinhardtii (C. reinhardtii), a photosynthetic unicellular green microalga, with C2C12 myoblasts in a hydrogel matrix. Leveraging the photosynthetic activity of C. reinhardtii, our microalgae-empowered muscle (MAM) constructs exhibited superior contractility and almost three times higher active force generation compared to conventional muscle constructs. MAM showed higher cellular viability and reduced tissue damage, attributed to in situ oxygenation and nutrient supply provided by microalgal photosynthesis. In addition, improved myotube alignment was observed in MAM, which contributed to enhanced force generation. Our findings showcase the potential of photosynthetic microalgae as a functional component in engineered skeletal muscle, offering a solution to longstanding challenges in muscle engineering.

DOI: https://doi.org/10.1126/sciadv.adw5786