Search Results (92)

Extracellular polymeric substances (EPSs) produced by actinomycetes of the genus Rhodococcus play crucial roles in their ecological success, metabolic versatility, and biotechnological value. This review summarizes existing studies of Rhodococcus EPSs, emphasizing the biochemical composition, functional attributes, and practical significance of EPSs, as well as their importance in biomedicine, bioremediation, and other applications (food industry, biomineralization) with respect to the EPS chemical composition and biological roles. Rhodococcus species synthesize complex EPSs composed primarily of polysaccharides, proteins and lipids that, like in other bacteria, support cell adhesion, aggregation, biofilm formation, and horizontal gene transfer (and can prevent exogenous DNA binding) and are highly important for resistance against toxicants and dissolution/assimilation of hydrophobic compounds. EPSs produced by different species of Rhodococcus exhibit diverse structures (soluble EPSs, loosely bound and tightly bound fractions, capsules, linear and branched chains, amorphous coils, rigid helices, mushroom-like structures, extracellular matrix, and a fibrillar structure with a sheet-like texture), leading to variations in their properties (rheological features, viscosity, flocculation, sorption abilities, compression, DNA binding, and interaction with hydrophobic substrates). Notably, the EPSs exhibit marked emulsifying and flocculating properties, contributing to their recognized role in bioremediation. Furthermore, EPSs possess antiviral, antibiofilm, anti-inflammatory, and anti-proliferating activities and high viscosity, which are valuable in terms of biomedical and food applications. Despite extensive industrial and environmental interest, the molecular regulation, biosynthetic pathways, and structural diversity of Rhodococcus EPSs remain insufficiently characterized. Advancing our understanding of these biopolymers could expand new applications in biomedicine, bioremediation, and biotechnology. Full article

The results of an experimental comparative study on absorptive nonlinear optical properties of deoxyribonucleic acid (DNA)–cetyltrimethylammonium chloride (CTMA) biopolymer functionalized with spirulina natural dye, as solutions in butanol, and on the same nonlinear optical properties of similar solutions with spirulina only, are presented. The spectroscopic characterisation of the investigated complexes is performed by Ultraviolet–Visible-Near-Infrared (UV-VIS-NIR) spectroscopy and Attenuated Total Reflection Fourier-transform Infrared (ATR-FTIR) spectroscopy. Their optical limiting functionality is experimentally demonstrated at the wavelength of 1550 nm (an important telecommunication wavelength) using ultrashort laser pulses (~120 fs). Important parameters that characterise the optical limiting (nonlinear absorption coefficient β, and saturation intensity, I_sat) are determined by the Intensity-scan (I-scan) method in the investigated materials. The results of our experimental investigation reveal, for the first time to the best of our knowledge, a significant absorptive nonlinear optical response of spirulina natural dye and its potential for optical limiting. The favourable effect of the DNA biopolymer on the nonlinear optical response of the investigated solutions, resulting in the enhancement of their nonlinear optical properties, is demonstrated. Thus, the investigated DNA–CTMA–spirulina liquid compound is a promising novel “green” material for passive optical limiting devices to protect sensitive optical and optoelectronic devices from high-intensity near-infrared laser beams. Also, from dye-doped DNA compounds as solutions it is possible to obtain, by different methods (e.g., spin-coating, drop casting), thin films as the base of all-optical solid-state limiting devices. Full article

The genus Billgrantia includes species with characteristics relevant to biotechnology. Several of these species can produce polyhydroxyalkanoates (PHAs), biodegradable biopolymers that play a role in adaptation to extreme conditions and have industrial applications. In this study, we describe a new species of the genus Billgrantia isolated from a sodium-saline soil in the community of Los Negritos, Villamar, Michoacán de Ocampo, Mexico. The strain LNSP4103-1^T was characterized at the genomic level using digital DNA-DNA hybridization and Average Nucleotide Identity (ANI) approaches. The difference indices between strain LNSP4103-1^T and the type strains (<86%) were below the threshold, supporting its classification as a novel species. The LNSP4103-1^T strain produced polyhydroxyalkanoates, with a maximum specific polymer yield of Y_PHA/X 0.71 g PHA g⁻¹ biomass and a yield Y_PHA/S 0.56 g PHA g⁻¹ glucose under conditions of 12.5% (w/v) NaCl and pH 7.5. Additionally, sucrose, mannitol, lactose and galactose were identified as substrates for PHA production. The draft genome version was deposited in the NCBI under the accession number JBMIQI000000000. The polyphasic analysis identified strain LNSP4103-1^T (TDS-413^T, CAIM 1962^T) as a new species. We proposed its taxonomic assignment as Billgrantia hypersalina sp. nov. Full article

Background/Objectives: Local delivery of gene therapy products through the airways shows great promise for the treatment of a number of serious lung diseases, but its effectiveness is hampered by the mucus layer protecting the lung epithelium in the trachea and bronchi. Methods: To overcome this barrier, we engineered carbon dots (CDs) with mucus penetrating properties. Results: The CDs were synthesized by solvothermal treatment of citric acid and branched polyethyleneimine, and functionalized with maleamic acid groups to create cationic mucoinert nanoparticles with tunable charge. We characterized their interactions with a mucus model through turbidity and transport measurements, and assessed their impact on the viscoelastic properties of the biopolymer. We then demonstrated that the carriers are effective at delivering pDNA to a variety of cell models in vitro. In particular, mucus-producing Calu-3 cells cultured at the air–liquid interface (ALI) were used as a discriminating model to evaluate intracellular delivery of the genetic cargo through a thick layer of mucus at the cell surface. Conclusions: The functionalization of CDs with maleamic acid groups resulted in a 1000- to 10,000-fold increase in transfection efficiency in the mucus-producing model, offering new opportunities for lung gene therapy. Full article

Polydeoxyribonucleotides (PDRN), highly purified DNA-derived polymers, were approved by the Italian Medicines Agency (AIFA) in 1994 to treat superficial wounds, skin ulcers, and dystrophic connective tissue disorders. Since then, PDRN have gained considerable attention as regenerative biomaterials. Beyond their established role in wound healing, they have also been approved as dermal fillers in several countries, with growing clinical evidence supporting their benefits for facial skin health. Recent clinical and preclinical studies suggest that PDRN may improve various skin conditions, including wrinkles, dryness, hyperpigmentation, hair loss, and barrier dysfunction. These findings have generated interest in their broader dermatological applications beyond traditional indications. This review aims to explore the therapeutic potential of PDRN for the treatment of skin disorders. We examine the efficacy and safety of PDRN-based drugs and medical devices in dermatology, with a focus on their clinical applications, pharmacological effects, and underlying molecular mechanisms. Given that PDRN consists of over 90% purified DNA, we further examine the biological functions of extracellular DNA (exDNA) and propose potential mechanisms by which PDRN may function as exDNA, beyond its classical action via the A2A receptor pathway. Collectively, current evidence highlights PDRN as safe and effective biopolymers with promising potential as DNA-based therapeutics in dermatology. Full article

Background/Objectives: Malignant neoplasms in children include leukemias. The main types are B-cell acute lymphoblastic leukemia (B-ALL) and acute myeloid leukemia (AML). Treatments are expensive, which is a particular problem in low-income countries. The main objective of this work was to develop specific nanosystems with small amounts of drug, allowing for affordable treatments. To this end, we designed ternary gold nanosystems (Au@16-Ph-16/DNA–Dauno) composed of daunomycin, a DNA biopolymer as a stabilizer, and the cationic surfactant gemini (TG) as a compacting agent for the DNA–daunomycin complex. Methods: Fluorescence, UV–visible, and CD spectroscopy, DLS and zeta potential, cell viability assays, TEM, AFM, and confocal microscopy were used to characterize and optimize nanocomposites. Results: The nanoparticles (Au@TG) obtained were small, stable, and highly charged in solution, allowing for optimal absorption and efficacy, capable of inducing the aggregation of the ternary nanosystem upon entering the cell, further enhancing its anticancer effect. Using nanoparticles, treatments can be redirected to the site of action, increasing the solubility and stability of the drug, minimizing the side effects of traditional treatments, and helping to overcome resistance to chemotherapy Conclusions: A significant decrease in the growth of pediatric B-ALL-derived cell lines (SEM and SUP-B15), constituting a potential and more affordable therapy for this type of pathology. Full article

Lignin, the second most abundant biopolymer in nature after cellulose, has attracted attention for its compatibility with carbon-based materials. In this study, lignin-modified single-use pencil graphite electrodes (PGE/LG) were developed for the electrochemical detection of fish sperm DNA (fsDNA), the anticancer drug Mitomycin C (MC), and their interaction. The modified electrodes were characterized using field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. Differential pulse voltammetry (DPV) in ferri/ferrocyanide redox probe solution was employed for signal monitoring. The detection limits were calculated as 2.95 ng/mL for fsDNA between 10¹ and 10⁵ ng/mL and 0.22 pg/mL for MC between 1 and 10⁶ pg/mL. Furthermore, the interaction of DNA with MC was evaluated by DPV and EIS techniques. The cross-linking between MC and the guanine bases of DNA inhibited electron transfer, resulting in a decrease in current response and an increase in charge transfer resistance. These results demonstrate the potential of the PGE/LG platform as a cost-effective, sensitive, and rapid biosensor for DNA detection, anticancer drug analysis, and drug–DNA interaction studies. Full article

Polynucleotide (PN) and polydeoxyribonucleotide (PDRN) are DNA-derived biopolymers increasingly recognized for their potential in dermatology. Despite their structural similarities, PN and PDRN exhibit distinct functions due to differences in polymer length and molecular weight. PN, composed of longer DNA fragments, plays a key role in extracellular matrix remodeling. Conversely, PDRN, composed of relatively shorter oligonucleotide sequences than those of PN, enhances skin condition through adenosine receptor activations and supports nucleotide synthesis via both the salvage and de novo pathways. This review provides a critical comparison of the molecular characteristics and functions of PN and PDRN with particular emphasis on their dermatological applications. By delineating their respective roles in esthetic and regenerative medicine, we aim to highlight recent advances that may guide the development of optimized treatment strategies and foster evidence-based clinical practice. Full article

Background: The aim of this review is to summarize and evaluate the properties of antibacterial polysaccharides for application in dental implantology to identify knowledge gaps and provide new research ideas. Methods: The electronic databases PubMed, Medline, ProQuest, and Google Scholar were used to search for peer-reviewed scientific publications published between 2018 and 2025 that provide insights to answer research questions on the role of antibacterial polysaccharides in combating pathogens in dental implantology without triggering immune reactions and inflammation. Further research questions relate to the efficacy against various dental pathogens and the understanding of the antibacterial mechanism, which may enable the development of functionalized polysaccharides with long-term antibacterial activity. Results: Biomedical implants have revolutionized medicine but also increased the risk of infections. Implant infections are a major problem in implantology and lead to implant failure and replacement. An antibacterial coating could be an excellent strategy to extend the lifespan of implants and improve the quality of the patient’s life. Bacterial resistance to antibiotics poses significant challenges for researchers, forcing them to search for new ways to prevent bacterial infections in implantology. Antibacterial natural polymers have recently received considerable research attention due to their long-term antibacterial activity. Polysaccharides from marine sources, such as chitosan and alginate, or pectin, xanthan, etc., from various plants, appear to be promising biopolymers for such applications in implantology due to their antibacterial activity, biocompatibility, and osteogenic properties. The antibacterial activity of these natural biopolymers depends on their chemical and physical properties. Nanopolysaccharides exhibit higher antibacterial activity than conventional polysaccharides, but their toxicity to human cells must be considered. Their antibacterial activity is based on the disruption of bacterial DNA or RNA synthesis, increased cell wall permeability, membrane disruption, and cytoplasmic leakage. Conclusions: Polysaccharides are a class of natural polymers with a broad spectrum of biological activities. They exhibit antioxidant, immunomodulatory, anticoagulant, anticancer, anti-inflammatory, antibacterial, and antiviral activity. Furthermore, polysaccharides are non-cytotoxic and exhibit good biocompatibility with osteogenic cells. Bactericidal polysaccharides are attractive new antibacterial materials against implant infections and open up new perspectives in implantology. Full article

We present the creation of an alignment layer for liquid crystal molecules based on DNA from fish waste and a selected cationic surfactant. The implemented biodegradable DNA-based surface offers excellent optical and physical properties, cost-effectiveness, and environmental benefits compared to conventional polymers. Our findings demonstrate that the biopolymer DNA-DODA effectively induces homeotropic alignment of nematic liquid crystals, which was confirmed by topography visualization using atomic force microscopy, macroscopy, and polarizing optical microscopy observations. Anchoring energy and response time studies in the well-known electro-optical effect show that DNA-DODA exhibits molecular interaction strengths comparable to those of commercial polyimide. The successful implementation of DNA-DODA as an alignment layer highlights its promise for next-generation technologies, including flexible, sustainable, and biocompatible optical devices. Full article

Two-dimensional nanomaterials (2DNMs) exhibit significant potential for the development of functional and specifically targeted biosensors, owing to their unique planar nanosheet structures and distinct physical and chemical properties. Biomodification and biomimetic synthesis offer green and mild approaches for the fabrication of multifunctional nanohybrids with enhanced catalytic, fluorescent, electronic, and optical properties, thereby expanding their utility in constructing high-performance biosensors. In this review, we present recent advances in the synthesis of 2DNM-based nanohybrids via both biomodification and biomimetic strategies for biosensor applications. We discuss covalent and non-covalent biomodification methods involving various biomolecules, including peptides, proteins, DNA/RNA, enzymes, biopolymers, and bioactive polysaccharides. The engineering of biomolecule–nanomaterial interfaces for the creation of biomodified 2DNM-based nanohybrids is also explored. Furthermore, we summarize the biomimetic synthesis of 2DNM-based bio–nanohybrids through pathways such as bio-templating, biomolecule-directed self-assembly, biomineralization, and biomimetic functional integration. The potential applications of these nanohybrids in diverse biosensing platforms—including colorimetric, surface plasmon resonance, electrochemical, fluorescence, photoelectrochemical, and integrated multimodal biosensors—are introduced and discussed. Finally, we analyze the opportunities and challenges associated with this rapidly developing field. We believe this comprehensive review will provide valuable insights into the biofunctionalization of 2DNMs and guide the rational design of advanced biosensors for diagnostic applications. Full article

In this study, the photophysical properties of thin films of an Eu³⁺ dye, namely europium tetrakis(dibenzoylmethide) triethylammonium (EuD₄TEA), within deoxyribonucleic acid (DNA) biopolymer functionalized with hexadecyltrimethylammonium chloride (CTMA) were extensively investigated and compared with those of thin films of the same dye embedded in more conventional polymers, like poly(methyl methacrylate) and polycarbonate. The new materials obtained have good optical properties, as shown by their absorption and emission spectra. Remarkably, a large enhancement in photoluminescence was observed upon the interaction of EuD₄TEA with DNA-CTMA (2- and 17-fold increase in luminescence quantum yield with respect to PMMA and PC). Photophysical analyses suggest that the emission enhancement was mainly due to the increase in the sensitization efficiency (η_sens) from the ligands to the Eu³⁺ ion along with the suppression of the vibrational deactivation upon immobilization onto the DNA-CTMA matrix, as the concentration of the complex increased from 20 to 50%. These phenomena are primarily driven by the transformation of the Eu³⁺ micro-environments, which are created by the interactions between complex ligands and the DNA-CTMA matrix. Full article

Polydeoxyribonucleotides (PDRNs) and polynucleotides (PNs) are similar DNA-derived biopolymers that have garnered significant scientific attention since the 1990s for their potential applications in wound healing and skin rejuvenation. These biopolymers exhibit a broad molecular weight (MW) range, typically spanning from 50 to 1500 kDa. However, recent studies have expanded this range to encompass fragments as small as 1 kDa and as large as 10,000 kDa. Clinically, PDRN/PN formulations, commercially available in various galenic forms (gels, creams, serums, masks, and injectables), have demonstrated promising effects in significantly promoting skin regeneration, reducing inflammation, improving skin texture, preventing scar formation, and mitigating wrinkles. Importantly, despite their widespread use in cosmetology and aesthetic dermatology, the interchangeable use of the terms “PDRN” and “PN” in the scientific literature (to describe polymers of varying lengths) has led to considerable confusion within the medical and scientific communities. To specifically address this PDRN/PN ambiguity, this narrative review proposes a standardized structure-based nomenclature for these DNA-derived polymers, the “Marques Polynucleotide Cutoff”, set at 1500 kDa. Thus, we propose that the term “PDRN” should be exclusively reserved for small- and medium-chain polymers (MW < 1500 kDa), while the term “PN” should specifically be used to denote longer-chain polymers (MW ≥ 1500 kDa). In a broader perspective, this classification is based on the distinct physicochemical properties and therapeutic effects of these DNA fragments of various MWs, which are comprehensively discussed in the present review. Full article

Sulfonated indocyanines 3 and 5 (sCy3, sCy5) are widely used to label biomolecules. Their high molar absorption coefficients and lack of spectral overlap with biopolymers make them ideal as linker components for rapid assessment of bioconjugate stoichiometry. We recently found that the determination of the sCy3:sCy5 molar ratio in a conjugate from its optical absorption spectrum is not straightforward, as the sCy3:sCy5 absorbance ratio at the maxima tends to be larger than expected. In this work, we have investigated this phenomenon in detail by studying the spectral properties of a series of sCy3-sCy5 conjugates in which the dyes are separated by linkers of various lengths, including DNA duplexes. It was found that when sCy3 and sCy5 are located in close proximity, they consistently exhibit an “abnormal” absorbance ratio. However, when the two dyes are separated by long rigid DNA-based spacers, the absorbance ratio becomes consistent with their individual molar absorption coefficients. This phenomenon should be taken into account when assessing the molar ratio of the dyes by UV-Vis spectroscopy. Full article

Bacterial cellulose (BC) is a versatile biopolymer with significant potential across biomedical, food, and industrial applications. To remove bacterial contaminants, such as protein and DNA, BC pellicles undergo purification, which traditionally relies on harsh alkali treatments, such as sodium hydroxide or strong surfactants, which present environmental concerns. In response, this study evaluates the efficacy of various non-conventional surfactants—both non-biodegradable and biodegradable—as alternatives for BC purification. Among the surfactants tested, sodium cocoyl isethionate (SCI), a mild anionic and biodegradable surfactant, emerged as particularly effective, achieving an 80.7% reduction in protein content and a 65.19% reduction in double-stranded DNA (dsDNA) content relative to untreated samples. However, these advantages were not without additional challenges, such as the appearance of residual surfactants. Given SCI’s promising performance and biodegradability, it was further examined in two-step treatment protocols; additionally, sodium dodecyl sulfate (SDS) was also examined as a more traditional anionic surfactant as well as NaOH. For the two-step treatment protocol, BC pellicles were treated with one reagent for 3 h, followed by a second reagent for an additional 3 h. Notably, by using NaOH as the final step in the two-step treatment protocol, residual surfactant was not detected in the FTIR analysis. Overall, this work demonstrates that SCI, in addition to subsequent NaOH treatment, can be used as a surfactant-based approach for BC purification, representing a potential environmentally friendly alternative to traditional surfactant-based approaches for BC purification. Full article