Search Results (56)

Human adipose biology is strongly influenced by three-dimensional (3D) architecture, cell–cell interactions, and local oxygen availability maintained over a long-term culture period, features that are not reproduced in traditional two-dimensional (2D) culture systems. To address this gap, we established a long-term human adipose-derived stem cell (hASC) spheroid model using elastin-like polypeptide–polyethyleneimine (ELP-PEI) coating. The ELP-PEI coating facilitated stable spheroid formation and sustained adipogenic differentiation over 56 days. As spheroids enlarged and matured, they exhibited hallmark features of adipocytes, including lipid accumulation, morphological compaction, and transition out of the proliferative state. Glucose uptake increased during maturation and declined as spheroids became larger. This reduction coincided with a marked rise in hypoxia-inducible factor-1α (HIF-1α) expression, indicating the emergence of a hypoxic microenvironment within larger spheroids. Notably, inhibiting HIF-1α restored insulin-stimulated glucose uptake, demonstrating that hypoxia was the primary driver of impaired insulin responsiveness in late-stage spheroids. These findings position ELP-PEI-supported hASC spheroids as a practical and physiologically relevant platform for studying human adipocyte biology, particularly the development and reversibility of hypoxia-associated metabolic dysfunction. This model offers new opportunities for mechanistic studies and for evaluating therapeutic strategies targeting insulin resistance and adipose tissue pathology. Full article

This review presents a comprehensive analysis of modern thermosensitive polymer systems for in situ systems (ISSs) which are used for targeted drug delivery in situ. The main classes of polymers used to create “smart” hydrogels that undergo a “sol–gel” phase transition in response to a temperature stimulus in the physiological range are considered. Key representatives of thermosensitive matrices are described in detail: synthetic block copolymers (poloxamers, block copolymers of polylactic-co-polyglycolic acid with polyethyleneglycol, etc.) and natural, modified natural, and semi-synthetic polymers (chitosan, including in combination with β-glycerophosphate, xyloglucan, etc.). This paper systematizes the advantages and disadvantages of various thermosensitive systems and highlights the key risks in their pharmaceutical development, including the influence of the nature and concentration of the active pharmaceutical ingredients and excipients on the rheological properties and phase transition temperature. Particular attention is paid to the difference between thermoreversible and irreversible gel-forming systems. Modern in vitro, ex vivo, and in vivo methods for evaluating critical quality parameters of thermosensitive systems, such as gelation temperature and time, gel strength, mucoadhesive properties, and release kinetics, are discussed. The need to develop standardized and biologically relevant methods to improve the reproducibility and success of preclinical studies is emphasized. The review is intended to help researchers to make informed choices about polymer matrices and optimize compositions for successful pharmaceutical development. Full article

Glioblastoma, with a 5-year survival rate of just under 7.0%, is the most common form of brain cancer in adults. In this study, we evaluated the antiproliferative activity of the biopolymer p21-ELP1-Bac, a p21-derived peptide delivered via an elastin-like polypeptide (ELP1) carrier and a cell-penetrating peptide (CPP), across three glioblastoma cell lines: U87, GBM43, and GBM6. We assessed proliferation, cell cycle progression, and apoptosis to determine whether ELP-mediated intracellular delivery of p21-ELP1-Bac suppresses glioblastoma growth through cytostatic mechanisms rather than inducing apoptosis. Treatment with the modified protein effectively inhibited proliferation across all three lines, with U87 cells showing the greatest sensitivity and GBM6 cells demonstrating the greatest drug tolerance. Although apoptotic responses were generally low, they appeared more pronounced in GBM6 cells. Confocal microscopy revealed sustained cellular uptake and signal observed in both the cytoplasm and in proximity to the nucleus in all cell lines. Collectively, these findings indicate that p21-ELP1-Bac is efficiently internalized and capable of modulating proliferation across all three glioblastoma cell lines, supporting its further evaluation as a cytostatic delivery platform. Full article

Chitosan oligosaccharides (COSs) with defined degrees of polymerization (DP) exhibit distinct bioactivities with promising applications in food, pharmaceutical, and agricultural industries. However, the specific and sustainable production of COSs remains challenging due to the broad product distribution of wild-type chitosanases and the difficulties in enzyme recovery and reuse. In this study, we employed rational design to engineer a GH46 chitosanase (CsnB) from Bacillus sp. BY01 for chitobiose production. Through homology modeling and molecular docking analysis, 15 mutants were designed by targeting key residues structurally critical for substrate stabilization, product release, and active-site geometry in the substrate-binding subsites. The D78Y mutant exhibited exclusive specificity for chitobiose, demonstrating a specific activity of 102.4 U/mg and yielding chitobiose with a purity exceeding 98%, thereby surpassing the previously reported enzymes for chitobiose production. To address the challenges of enzyme stability, purification costs, and product separation, we developed a ReELP system by integrating elastin-like polypeptides (ELPs) with a ReverseCatcher/ReverseTag peptide pair. This system enabled one-step purification and co-immobilization of CsnB-D78Y directly from cell lysate onto biomimetic silica nanoparticles, achieving 96.8% immobilization efficiency and 90.7% activity recovery. The immobilized enzyme exhibited enhanced thermal and pH stability, retaining approximately 50% activity after 12 h at 40 °C compared to only 5.7% for the free enzyme. In reusability assays, the immobilized CsnB-D78Y maintained efficient chitobiose production over 5 consecutive cycles. This work provides a green and cost-effective strategy for the specific and sustainable production of chitobiose, offering new insights into enzyme engineering and immobilization for industrial COS production. Full article

Cellular senescence is a major barrier to the therapeutic application of human mesenchymal stem cells (hMSCs), as it compromises their proliferative capacity, differentiation potential, and regenerative efficacy. In this study, we investigated whether FN9-10ELP, a recombinant extracellular matrix (ECM)-mimetic fusion protein composed of fibronectin type III domains 9 and 10 conjugated to elastin-like polypeptides (ELPs), could attenuate etoposide-induced senescence in human turbinate-derived MSCs (hTMSCs). Premature senescence was induced by treatment with 20 µM etoposide, and the protective effects of FN9-10ELP were evaluated in terms of cell viability (using the MTT assay), senescence-associated gene expression (by RT-qPCR analysis), nuclear morphology (after staining with 4’,6-diamidino-2-phenylindole (DAPI)), and SA-β-galactosidase activity. FN9-10ELP treatment significantly improved cell viability and reduced the expression of senescence-associated secretory phenotype (SASP) genes, including interleukin-6 (IL-6), interleukin-8 (IL-8), and plasminogen activator inhibitor-1 (PAI-1). Furthermore, FN9-10ELP alleviated nuclear enlargement and decreased the proportion of SA-β-gal-positive cells, indicating suppression of the senescence phenotype. These findings demonstrate that FN9-10ELP effectively counteracts chemotherapy-induced senescence in hMSCs and highlight its potential as a promising biomaterial for regenerative medicine and anti-aging therapies. Full article

To achieve the large-scale, low-cost preparation of acetaldehyde lyase (ALS), elastin-like polypeptides (ELPs) as non-chromatographic purification tags were employed to develop an ELP-ALS fusion protein in Escherichia coli. Induction expression results demonstrated that the ELPs tag efficiently improved the soluble expression of the ALS enzyme. Through two rounds of inverse transition cycling (ITC), highly pure ELP-ALS was obtained with an enzyme recovery rate of 85.77%, outperforming Ni²⁺-affinity chromatography (66.80%). The comparative analysis of enzymatic properties revealed that ELP fusion markedly improved the stability and substrate tolerance of the ALS enzyme. Kinetic parameter analysis under identical conditions showed that ELP-ALS possessed a V_max of 15.25 U/mg and a k_cat/K_m of 73.05 s⁻¹·M⁻¹, representing 1.86-fold and 2.97-fold improvements over His-ALS, respectively. Fed-batch reaction using ELP-ALS and acetaldehyde as biocatalyst and substrate, respectively, yielded 95.92 g/L acetoin with 49.32% increase compared to His-ALS (64.24 g/L). These results demonstrated the application potential of ELP-ALS as a promising biocatalyst for acetoin production from acetaldehyde due to its lower preparation cost, higher biocatalytic efficiency, better stability, and substrate tolerance. Full article

Precise control of protein translocation is essential for synthetic biology and protein engineering. Here, we present a temperature-responsive system using elastin-like polypeptides (ELPs) to regulate the translocation of a conditionally lethal enzyme in Escherichia coli. The enzyme, levansucrase, whose activity becomes lethal in the presence of sucrose, was engineered with an N-terminal signal peptide and a C-terminal ELP tag. At 37 °C, the ELP tag induced intracellular aggregation of the fusion protein, preventing its secretion and allowing cell survival, as indicated by translucent colony formation. In contrast, at 16 °C, the ELP remained soluble, permitting levansucrase secretion into the medium. The resulting conversion of sucrose into levan by the secreted enzyme led to host cell death. These findings highlight ELP-mediated aggregation as a reversible and tunable strategy for regulating protein localization and secretion in E. coli, with potential applications in synthetic biology, metabolic engineering, and biocontainment systems. Full article

Recombinant protein hydrogels have emerged as transformative biomaterials that overcome the bioinertness and unpredictable degradation of traditional synthetic systems by leveraging genetically engineered backbones, such as elastin-like polypeptides, SF, and resilin-like polypeptides, to replicate extracellular matrix (ECM) dynamics and enable programmable functionality. Constructed through a hierarchical crosslinking strategy, these hydrogels integrate reversible physical interactions with covalent crosslinking approaches, collectively endowing the system with mechanical strength, environmental responsiveness, and controlled degradation behavior. Critically, molecular engineering strategies serve as the cornerstone for functional precision: domain-directed self-assembly exploits coiled-coil or β-sheet motifs to orchestrate hierarchical organization, while modular fusion of bioactive motifs through genetic encoding or site-specific conjugation enables dynamic control over cellular interactions and therapeutic release. Such engineered designs underpin advanced applications, including immunomodulatory scaffolds for diabetic wound regeneration, tumor-microenvironment-responsive drug depots, and shear-thinning bioinks for vascularized bioprinting, by synergizing material properties with biological cues. By uniting synthetic biology with materials science, recombinant hydrogels deliver unprecedented flexibility in tuning physical and biological properties. This review synthesizes emerging crosslinking paradigms and molecular strategies, offering a framework for engineering next-generation, adaptive biomaterials poised to address complex challenges in regenerative medicine and beyond. Full article

Three-dimensional (3D) in vitro adipocyte models provide physiologically relevant platforms for studying adipogenesis and obesity-related metabolic dysfunction. However, long-term adipocyte culture is often hindered by limited cell–matrix adhesion and spheroid detachment. Previously, we demonstrated that elastin-like polypeptide (ELP)–polyethyleneimine (PEI) coatings functionalized with a trivalent RGD motif enhanced spheroid retention during frequent media changes. The present study investigates the long-term functional consequences of RGD incorporation over a 28-day culture period. 3T3-L1 preadipocytes were seeded, differentiated, and matured on ELP-PEI or ELP-(RGD)₃-PEI coatings. Spheroid morphology, triglyceride content, expression of PPAR-γ, adiponectin, HIF-1α genes, and insulin-stimulated glucose uptake were assessed. Both coatings supported initial spheroid formation, but only ELP-PEI maintained the 3D architecture and supported adipogenic maturation and insulin responsiveness. ELP-(RGD)₃-PEI promoted early retention but led to spheroid disassembly by mid-culture; notably, by day 28, cells reaggregated into abnormally large spheroids with impaired metabolic function, likely due to continued proliferation. These findings highlight the critical role of extracellular matrix-mediated cell–cell versus cell–substrate interactions in maintaining 3D culture fidelity. While RGD enhances adhesion, it disrupts spheroid integrity and compromises adipogenic and metabolic maturation. Taken together, ELP-PEI coatings offer a more conducive microenvironment for long-term 3D adipocyte culture and hold promise for modeling obesity-associated metabolic dysfunction in vitro. Full article

Conventional calcium silicate cement (CSC) formulations often exhibit insufficient mechanical strength and low initial stability. This study aimed to develop an organic–inorganic hybrid biomaterial by incorporating an elastin-like polypeptide (ELP) (V125E8) and bioactive glass (BG) (63S) into CSC to improve its mechanical properties and wash-out resistance during the initial setting. Experimental groups included ProRoot MTA (Dentsply Sirona, USA) as a control (0BG), inorganic hybrids containing BG (2% or 5%; 2BG, 5BG), and organic–inorganic hybrids combining BG (2% or 5%; 2BG-L, 5BG-L) with a 10 wt% ELP solution. The compressive strength, microhardness, and wash-out resistance of the specimens were evaluated. The organic–inorganic hybrid groups (2BG-L and 5BG-L) exhibited significantly higher compressive strength and microhardness than the control (0BG) and inorganic-only groups (2BG and 5BG). Additionally, the incorporation of ELP markedly improved wash-out resistance, minimizing material disintegration during the initial setting in aqueous environments. The organic–inorganic hybrid groups (2BG-L and 5BG-L) exhibited significantly higher compressive strength and microhardness than the control (0BG) and inorganic-only groups (2BG and 5BG). Additionally, the incorporation of ELP markedly improved wash-out resistance, minimizing material disintegration during the initial setting in aqueous environments. Full article

To mimic the important features of progressing adiposity, in vitro adipose cell culture models must allow gradual intracellular fat accumulation in the three-dimensional (3D) arrangement of adipose-derived stem cells (ASCs) over a long-term culture period. Previously, elastin-like polypeptide (ELP) and polyethyleneimine (PEI) have been used to culture human adipose-derived stem cells (hASCs) as 3D spheroids and to differentiate them to adipocytes over a relatively long culture period of up to 5 weeks. In this study, to further enhance the spheroid adhesion properties, ELP was fused with Arginine–Glycine–Aspartic Acid (RGD) residues, known for their role as cell-attachment sites. This study aimed to assess whether the addition of RGD to the C-or N-terminus of ELP would impact the spheroid-forming ability of ELP-PEI coatings. ELP-RGD conjugates were produced using genetically modified Escherichia coli to express ELP-(RGD)₃ and (RGD)₃-ELP, followed by chemical conjugation with PEI. SDS gel electrophoresis, FTIR spectroscopy, and turbidimetry analyses revealed that ELP was conjugated with RGD without much alteration in the molecular weight, functional groups present, and transition temperature of ELP. The addition of RGD to ELP also did not affect the chemical conjugation capacity of ELP to PEI. We observed that the ELP-PEI coating formed slightly larger spheroids (61.8 ± 3.2 µm) compared to the ELP-(RGD)₃-PEI and (RGD)₃-ELP-PEI coatings (56.6 ± 3.0 and 53.4 ± 2.4 µm, respectively). Despite the size difference, ELP-(RGD)₃-PEI coatings exhibited superior spheroid retention during media changes, with minimal spheroid loss. DNA assay results confirmed a significant decrease in the DNA concentration (p < 0.05) after the 20 media changes for spheroids cultured on the ELP-PEI coating, indicating spheroid loss. However, there was no significant difference in DNA concentration before and after 20 media changes for spheroids cultured on the ELP-(RGD)₃-PEI and (RGD)₃-ELP-PEI coatings (p > 0.05). These findings suggest that RGD incorporation does not hinder the initial spheroid formation ability of the ELP-PEI coating and enhances spheroid retention under dynamic culture conditions. Full article

HUG is the HELP-UnaG recombinant fusion protein featuring the typical functions of both HELP and UnaG. In HUG, the HELP domain is a thermoresponsive human elastin-like polypeptide. It forms a shield enwrapping the UnaG domain that emits bilirubin-dependent fluorescence. Here, we recapitulate the technological development of this bifunctional synthetic protein from the theoretical background of its distinct protein moieties to the detailed characterization of its macromolecular and functional properties. These pieces of knowledge are the foundations for HUG production and application in the fluorometric analysis of bilirubin and its congeners, biliverdin and bilirubin glucuronide. These bile pigments are metabolites that arise from the catabolism of heme, the prosthetic group of cytochromes, hemoglobin and several other intracellular enzymes engaged in electron transfer, oxygen transport and protection against oxygen free radicals. The HUG assay is a powerful, user-friendly and affordable analytical tool that alone supports research at each level of complexity or taxonomy of living entities, from enzymology, cell biology and pathophysiology to veterinary and clinical sciences. Full article

Protein purification is a crucial step for various downstream applications like drug development, antibody preparation, and structure determination. The constant pursuit is for methods that are more efficient and cost-effective. We propose a novel approach using an elastin-like polypeptide (ELP) as an aggregation core that serves as an anchor between the beads in a chromatography column. In this method, a chilled sample containing a [target protein type] fusion protein is loaded onto a pre-equilibrated IMAC (immobilized metal affinity chromatography) column with a low-salt buffer. The column is then washed with a warm buffer containing high salt to remove impurities. Here, the key step involves warming the column above the ELP’s transition temperature (Tt), which triggers its aggregation. This aggregation is expected to trap the target protein tightly between the beads. Subsequently, a harsh wash with high salt and high imidazole can be applied to remove even persistent contaminants, achieving high protein purity. Finally, the temperature is lowered, and a cold, low-salt buffer is introduced to reverse the aggregation and elute the purified target protein. This method has the potential to eliminate the need for sophisticated chromatography systems while still achieving high protein purity. Full article

This paper reports the development of a highly crosslinked hyper-branched polyglycerol (HPG) polymer bound to elastin-like proteins (ELPs) to create a membrane that undergoes a distinct closed-to-open permeation transition at 32 °C. The crosslinked HPG forms a robust, mesoporous structure (150–300 nm pores), suitable for selective filtration. The membranes were characterized by FTIR, UV–visible spectroscopy, SEM, and AFM, revealing their structural and morphological properties. Incorporating a synthetic polypeptide introduced thermo-responsive behavior, with the membrane transitioning from impermeable to permeable above the lower critical solution temperature (LCST) of 32 °C. Permeation studies using crystal violet (CV) demonstrated selective transport, where CV permeated only above 32 °C, while water permeated at all temperatures. This hybrid HPG-ELP membrane system, acting as a molecular switch, offers potential for applications in drug delivery, bioseparations, and smart filtration systems, where permeability can be controlled by temperature. Full article

(1) Background: This study aimed to enhance the biological properties of hydraulic calcium silicate cements (HCSCs) by incorporating organic and inorganic components, specifically elastin-like polypeptides (ELPs) and bioactive glass (BAG). We focused on the effects of these composites on the viability, migration, and osteogenic differentiation of human periodontal ligament fibroblasts (hPDLFs). (2) Methods: Proroot MTA was supplemented with 1–5 wt% 63S BAG and 10 wt% ELP. The experimental groups contained various combinations of HSCS with ELP and BAG. Cell viability was assessed using an MTT assay, cell migration was evaluated using wound healing and transwell assays, and osteogenic activity was determined through Alizarin Red S staining and a gene expression analysis of osteogenic markers (ALP, RUNX-2, OCN, and Col1A2). (3) Results: The combination of ELP and BAG significantly enhanced the viability of hPDLFs with an optimal BAG concentration of 1–4%. Cell migration assays demonstrated faster migration rates in groups with 2–4% BAG and ELP incorporation. Osteogenic activity was the highest with 2–3% BAG incorporation with ELP, as evidenced by intense Alizarin Red S staining and the upregulation of osteogenic differentiation markers. (4) Conclusions: The incorporation of ELP (organic) and BAG (inorganic) into HCSC significantly enhances the viability, migration, and osteogenic differentiation of hPDLFs. These findings suggest that composite HCSC might support healing in destructed bone lesions in endodontics. Full article