Nanoparticle-Biofilm Interactions: The Role of the EPS Matrix

Wound healing has been intensely studied in order to develop an “ideal” technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal agents, in order to prevent infection and promote a proper wound-healing process. Nanotechnology studies submicroscopic particles (maximum diameter of 100 nm), as well as correlated phenomena. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being used in dermatology, due to their beneficial effect on accelerating wound healing, as well as treating and preventing bacterial infections. Other benefits include: ease of use, less frequent dressing changes and a constantly moist wound environment. This review highlights recent findings regarding nanoparticle application in wound management.

https://www.mdpi.com/1996-1944/12/13/2176/pdf

Nanomaterials for Wound Healing and Infection Control.

Biofilm is the virulence factor that is responsible for chronic infection in diseases such as Cystic Fibrosis (CF) and chronic wounds. In this thesis, we examine the role of AlgX, a required protein for alginate biosynthesis in P. aeruginosa . We show that the absence of AlgX resulted in the loss of mucoidy and in silico studies demonstrated that AlgX binds alginate. Alanine mutations demonstrated that K396, T398, W400, and R406 are important for alginate binding. Alginate rescue assays confirm the importance of these amino acid residues for alginate biosynthesis and acetylation. This is the first functional demonstration of AlgX role in alginate biofilm biosynthesis and acetylation.Biofilm-producing bacteria and redox imbalance are the leading factors that turn acute wounds into chronic wounds. We demonstrated that LIGHT -/- mouse wounds contain elevated levels of reactive oxygen species (ROS). To see whether chronic wounds can be generated, we increased the redox imbalance in the LIGHT -/- wounds and infecting the wounds with biofilm-forming bacteria. We demonstrated that by using these conditions, we could induce chronic wounds in the LIGHT -/- mouse model 100% of the time. These wounds do not re-epithelialize, contain high bacterial burden, and sustained multi-species bacterial infections that are biofilm-forming and antibiotic-resistant.We also demonstrated that increasing the redox imbalance was sufficient to turn db/db wounds into chronic wounds. These wounds sustained spontaneous biofilm- producing bacterial infections. To verify that redox imbalance is critical for chronicity, we treated chronic wounds with antioxidants and found that oxidative stress was highly reduced, biofilm production was decreased, and bacteria became more sensitive to antibiotics. This is the first demonstration that chronic wounds can be generated and reversed by manipulating the wound's redox microenvironment in an animal model.Norspermidine has been shown to negatively affect the structure of extracellular polymeric substances (EPS). Using the bacteria that colonized db/db chronic wounds, we demonstrated that 2 mM norspermidine reduces the amount of adherent biofilms produced by exudate bacterial communities. Furthermore, application of norspermidine increases the bactericidal effect of gentamicin. We believe that norspermidine could be used in combination with bactericidal antibiotics to control biofilm infection in dermal chronic wounds.

/pdf/the-role-of-bacterial-biofilms-in-chronic-infections-15e6829i50.pdf

The Role of Bacterial Biofilms in Chronic Infections

The detection of clinically relevant disease-specific biomolecules, including nucleic acids, circulating tumor cells, proteins, antibodies, and extracellular vesicles, has been indispensable to understand their functions in disease diagnosis and prognosis. Therefore, a biosensor for the robust, ultrasensitive, and selective detection of these low-abundant biomolecules in body fluids (blood, urine, and saliva) is emerging in current clinical research. In recent years, nanomaterials, especially superparamagnetic nanomaterials, have played essential roles in biosensing due to their intrinsic magnetic, electrochemical, and optical properties. However, engineered multicomponent magnetic nanoparticle-based current biosensors that offer the advantages of excellent stability in a complex biomatrix; easy and alterable biorecognition of ligands, antibodies, and receptor molecules; and unified point-of-care integration have yet to be achieved. This review introduces the recent advances in superparamagnetic nanostructures for electrochemical and optical biosensing for disease-specific biomarkers. This review emphasizes the synthesis, biofunctionalization, and intrinsic properties of nanomaterials essential for robust, ultrasensitive biosensing. With a particular emphasis on nanostructure-based electrochemical and optical detection of disease-specific biomarkers such as nucleic acids (DNA and RNA), proteins, autoantibodies, and cells, this review also chronicles the needs and challenges of nanoarchitecture-based detection. These summaries provide further insights for researchers to inspire their future work on the development of nanostructures for integrating into biosensing and devices for a broad field of applications in analytical sensing and in clinic.

/pdf/superparamagnetic-nanoarchitectures-for-disease-specific-1hhi0ekxyf.pdf

Superparamagnetic nanoarchitectures for disease-specific biomarker detection

We report a nanoparticulate system capable of targeting the heart after myocardial infarction (MI). Targeting is based on overexpression of angiotensin II type 1 (AT1) receptor in the infarcted heart. Liposomes 142 nm in diameter were conjugated with a ligand specific to AT1. The nanoparticles were able to specifically target cardiac cells in vitro, and in the infarcted heart after intravenous injection in vivo. This system may be useful for delivering therapeutic agents specifically to the infarcted heart.

Nanoparticles for targeting the infarcted heart

The disadvantages that come with traditional cancer treatments, such as chemotherapy and radiotherapy, generated a research shift toward nanotechnology. However, even with the important advancements regarding cancer therapy, there are still serious stepping stones that need to be addressed. The use of both nanotechnology and nanomedicine has generated significant improvements in nano-sized materials development and their use as therapeutic, diagnosis, and imaging agents. The biological barriers that come from the healthy body, as well from the tumorous sites, are important parameters that need to be taken into consideration when designing drug delivery systems. There are several aspects of extreme importance such as the tumor microenvironment and vasculature, the reticuloendothelial system, the blood-brain barrier, the blood-tumor barrier, and the renal system. In order to achieve an effective system for cancer therapy, several characteristics of the nanoparticles have been outlined. Moreover, this review has also focused on the different types of nanoparticles that have been studied over the years as potential candidates for cancer therapy.

https://www.mdpi.com/1420-3049/24/19/3547/pdf

Nanobiomaterials Used in Cancer Therapy: An Up-To-Date Overview.

Wound healing involves a complex interaction between immunity and other natural host processes, and to succeed it requires a well-defined cascade of events. Chronic wound infections can be mono- or polymicrobial but their major characteristic is their ability to develop a biofilm. A biofilm reduces the effectiveness of treatment and increases resistance. A biofilm is an ecosystem on its own, enabling the bacteria and the host to establish different social interactions, such as competition or cooperation. With an increasing incidence of chronic wounds and, implicitly, of chronic biofilm infections, there is a need for alternative therapeutic agents. Nanotechnology shows promising openings, either by the intrinsic antimicrobial properties of nanoparticles or their function as drug carriers. Nanoparticles and nanostructured coatings can be active at low concentrations toward a large variety of infectious agents; thus, they are unlikely to elicit emergence of resistance. Nanoparticles might contribute to the modulation of microbial colonization and biofilm formation in wounds. This comprehensive review comprises the pathogenesis of chronic wounds, the role of chronic wound colonization and infection in the healing process, the conventional and alternative topical therapeutic approaches designed to combat infection and stimulate healing, as well as revolutionizing therapies such as nanotechnology-based wound healing approaches.

Nanocoatings for Chronic Wound Repair—Modulation of Microbial Colonization and Biofilm Formation

Oxidative stress has been linked with a variety of diseases, being involved in the debut and/or progress of several neurodegenerative disorders. This review intends to summarize some of the findings that correlate the overproduction of reactive oxygen species with the pathophysiology of Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. Oxidative stress was also noted to modify the inflammatory response. Even though oxidative stress and neuroinflammation are two totally different pathological events, they are linked and affect one another. Nonetheless, there are still several mechanisms that need to be understood regarding the onset and the progress of neurodegenerative diseases in order to develop efficient therapies. As antioxidants are a means to alter oxidative stress and slow down the symptoms of these neurodegenerative diseases, the most common antioxidants, enzymatic as well as non-enzymatic, have been mentioned in this paper as therapeutic options for the discussed disorders.

/pdf/an-overview-of-oxidative-stress-neuroinflammation-and-e7744kdm.pdf

An Overview of Oxidative Stress, Neuroinflammation, and Neurodegenerative Diseases

In the last decade, nanobiotechnology has evolved rapidly with an extensive impact on biomedical area. In order to improve bioavailability and minimize adverse effects, drug delivery systems based on magnetic nanocomposites are under development mainly for cancer imaging and antitumor therapy. In this regard, pH sensitive core-shell magnetic nanoparticles (NPs) with accurate controlled size and shape are synthesized by various modern methods, such as homogeneous precipitation, coprecipitation, microemulsion or polyol approaches, high temperature and hydrothermal reactions, sol-gel reactions, aerosol÷vapor processes and sonolysis. Due to their unique combined physico-chemical and biological properties (such as higher dispensability, chemical and thermal stability, biocompatibility), pH responsive core-shell magnetic NPs are widely investigated for controlled release of cytostatic drugs into the tumor site by means of pH change: magnetite@silicon dioxide (Fe3O4@SiO2), Fe3O4@titanium dioxide (TiO2), β-thiopropionate-polyethylene glycol (PEG)-modified Fe3O4@mSiO2, Fe3O4 NPs core coated with SiO2 with an imidazole group modified PEG-polypeptide (mPEG-poly-L-Asparagine), polyacrylic acid (PAA) and folic acid (FA) coating of the iron oxide NP core, methoxy polyethylene glycol-block-polymethacrylic acid-block-polyglycerol monomethacrylate (MPEG-b-PMAA-b-PGMA) attached by a PGMA block to a Fe3O4 core, PEG-modified polyamidoamine (PAMAM) dendrimer shell with Fe3O4 core and mesoporous silica coated on Fe3O4, mostly coated with an anticancer drug. This review paper highlights the modern research directions currently employed to demonstrate the utility of the pH responsive core-shell magnetic NPs in diagnosis and treatment of oncological diseases.

pH sensitive core-shell magnetic nanoparticles for targeted drug delivery in cancer therapy.

The study of magnetism in materials without partially filled d or f bands has gained much attention in the past years. Even though it has challenged the understanding of traditional magnetism, there is a wide range of studies debating the nature of magnetism in such materials. Theories on whether the exhibited ferromagnetic behavior is due to sample impurities or intrinsic structural defects have been published throughout the years. Materials such as hexaborides, non-magnetic oxides, and carbon nanostructures have been of great interest due to their potential applications. For a better understanding, herein, we present a literature review combining past and up-to-date studies on these materials.

Iulia Ioana Lungu

Papers

Nanobiomaterials Used in Cancer Therapy: An Up-To-Date Overview.

Nanocoatings for Chronic Wound Repair—Modulation of Microbial Colonization and Biofilm Formation

An Overview of Oxidative Stress, Neuroinflammation, and Neurodegenerative Diseases

pH sensitive core-shell magnetic nanoparticles for targeted drug delivery in cancer therapy.

Unexpected Ferromagnetism—A Review