Porous antioxidant polymer microparticles as therapeutic systems for the airway inflammatory diseases

Nanomotors as Therapeutic Agents: Advancing Treatment Strategies for Inflammation-Related Diseases

Inflammation is a physiological response of the body to harmful stimuli such as pathogens, damaged cells, or irritants, involving a series of cellular and molecular events. It is associated with various diseases including neurodegenerative disorders, cancer, and atherosclerosis, and is a leading cause of global mortality. Key inflammatory factors, such as Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1 (IL-1), Interleukin-6 (IL-6), Monocyte Chemoattractant Protein-1 (MCP-1/CCL2), RANTES (CCL5), and prostaglandins, play central roles in inflammation and disease progression. Traditional treatments such as NSAIDs, steroids, biologic agents, and antioxidants have limitations. Recent advancements in nanomaterials present promising solutions for treating inflammation-related diseases. Unlike nanomaterials that rely on passive targeting and face challenges in precise drug delivery, nanomotors, driven by chemical or optical stimuli, offer a more dynamic approach by actively navigating to inflammation sites, thereby enhancing drug delivery efficiency and therapeutic outcomes. Nanomotors allow for controlled drug release in response to specific environmental changes, such as pH and inflammatory factors, ensuring effective drug concentrations at disease sites. This active targeting capability enables the use of smaller drug doses, which reduces overall drug usage, costs, and potential side effects compared to traditional treatments. By improving precision and efficiency, nanomotors address the limitations of conventional therapies and represent a significant advancement in the treatment of inflammation-related diseases. This review summarizes the latest research on nanomotor-mediated treatment of inflammation-related diseases and discusses the challenges and future directions for optimizing their clinical translation.

Appraisal terpenoids rich Boswellia carterri ethyl acetate extract in binary cyclodextrin oligomer nano complex for improving respiratory distress

Boswellia carterii (BC) resins plants have a long historical background as a treatment for inflammation, as indicated by information originating from multiple countries. Twenty-seven diterpenoids have been identified in ethyl acetate and total methanol BC, comprising seventeen boscartins of the cembrane-type diterpenoids and ten boscartols of the prenylaromadendrane-type diterpenoids. Moreover, twenty-one known triterpenoids have also been found, encompassing nine tirucallane-type, six ursane-type, four oleanane-type, and two lupane-type. The cembrane-type diterpenoids hold a significant position in pharmaceutical chemistry and related industries due to their captivating biological characteristics and promising pharmacological potentials. Extraction of BC, creation and assessment of nano sponges loaded with either B. carterii plant extract or DEX, are the subjects of our current investigation. With the use of ultrasound-assisted synthesis, nano sponges were produced. The entrapment efficiency (EE%) of medications in nano sponges was examined using spectrophotometry. Nano sponges were characterized using a number of methods. Within nano sponges, the EE% of medicines varied between 98.52 ± 0.07 and 99.64 ± 1.40%. The nano sponges' particle sizes varied from 105.9 ± 15.9 to 166.8 ± 26.3 nm. Drugs released from nano sponges using the Korsmeyer-Peppas concept. In respiratory distressed rats, the effects of BC plant extract, DEX salt and their nano formulations (D1, D5, P1 and P1), were tested. Treatment significantly reduced ICAM-1, LTB4, and ILβ 4 levels and improved histopathologic profiles, when compared to the positive control group. Boswellia extract and its nano sponge formulation P1 showed promising therapeutic effects. The effect of P1 may be due to synergism between both the extract and the formulation. This effect was achieved by blocking both ICAM-1 and LTB4 pathways, therefore counteracting the effects of talc powder.

Microparticles in the Development and Improvement of Pharmaceutical Formulations: An Analysis of In Vitro and In Vivo Studies

Microparticulate systems such as microparticles, microspheres, microcapsules or any particle in a micrometer scale (usually of 1–1000 µm) are widely used as drug delivery systems, because they offer higher therapeutic and diagnostic performance compared to conventional drug delivery forms. These systems can be manufactured with many raw materials, especially polymers, most of which have been effective in improving the physicochemical properties and biological activities of active compounds. This review will focus on the in vivo and in vitro application in the last decade (2012 to 2022) of different active pharmaceutical ingredients microencapsulated in polymeric or lipid matrices, the main formulation factors (excipients and techniques) and mostly their biological activities, with the aim of introducing and discussing the potential applicability of microparticulate systems in the pharmaceutical field.

Degradable polyprodrugs: design and therapeutic efficiency

Prodrugs are developed to increase the therapeutic properties of drugs and reduce their side effects. Polyprodrugs emerged as highly efficient prodrugs produced by the polymerization of one or several drug monomers. Polyprodrugs can be gradually degraded to release therapeutic agents. The complete degradation of polyprodrugs is an important factor to guarantee the successful disposal of the drug delivery system from the body. The degradation of polyprodrugs and release rate of the drugs can be controlled by the type of covalent bonds linking the monomer drug units in the polymer structure. Therefore, various types of polyprodrugs have been developed based on polyesters, polyanhydrides, polycarbonates, polyurethanes, polyamides, polyketals, polymetallodrugs, polyphosphazenes, and polyimines. Furthermore, the presence of stimuli-responsive groups, such as redox-responsive linkages (disulfide, boronate ester, metal-complex, and oxalate), pH-responsive linkages (ester, imine, hydrazone, acetal, orthoester, P-O and P-N), light-responsive (metal-complex, o-nitrophenyl groups) and enzyme-responsive linkages (ester, peptides) allow for a selective degradation of the polymer backbone in targeted tumors. We envision that new strategies providing a more efficient synergistic therapy will be developed by combining polyprodrugs with gene delivery segments and targeting moieties.

The Pharmacokinetics in Mice and Cell Uptake of Thymus Immunosuppressive Pentapeptide Using LC-MS/MS Analysis

Thymus immunosuppressive pentapeptide (TIPP) is a novel anti-inflammatory peptide with high efficacy and low toxicity. This study aims to establish a selective LC-MS/MS method for analyzing the analyte TIPP in biological samples, laying the foundation for further PK and PD studies of TIPP. Protein precipitation was conducted in acetonitrile supplemented with 2% formic acid and 25 mg/mL dithiothreitol as a stabilizer, which was followed by backwashing the organic phase using dichloromethane. The chromatographic separation of TIPP was achieved on a C18 column with a gradient elution method. During positive electrospray ionization, TIPP was analyzed via multiple-reaction monitoring. The linear relationships between the concentration of TIPP and peak area in murine plasma cell lysates, supernatants, and the final cell rinse PBS were established within the ranges of 20−5000 ng/mL, 1−200 ng/mL, 10−200 μg/mL, and 0.1−20 ng/mL, respectively (r2 > 0.99). Validated according to U.S. FDA guidelines, the proposed method was proved to be acceptable. Such a method had been successfully applied to investigate the pharmacokinetics of TIPP in mice via subcutaneous injection. The plasma half-life in mice was 5.987 ± 1.824 min, suggesting that TIPP is swiftly eliminated in vivo. The amount of TIPP uptake by RBL-2H3 cells was determined using this method, which was also visually verified by confocal. Furthermore, the effective intracellular concentration of TIPP was deduced by comparing the intracellular concentration of TIPP and degrees of inflammation, enlightening further investigation on the intracellular target and mechanism of TIPP.

Integrating Inflammation-Responsive Prodrug with Electrospun Nanofibers for Anti-Inflammation Application

Chronic inflammation plays a side effect on tissue regeneration, greatly inhibiting the repair or regeneration of tissues. Conventional local delivery of anti-inflammation drugs through physical encapsulation into carriers face the challenges of uncontrolled release. The construction of an inflammation-responsive prodrug to release anti-inflammation drugs depending on the occurrence of inflammation to regulate chronic inflammation is of high need. Here, we construct nanofiber-based scaffolds to regulate the inflammation response of chronic inflammation during tissue regeneration. An inflammation-sensitive prodrug is synthesized by free radical polymerization of the indomethacin-containing precursor, which is prepared by the esterification of N-(2-hydroxyethyl) acrylamide with the anti-inflammation drug indomethacin. Then, anti-inflammation scaffolds are constructed by loading the prodrug in poly(ε-caprolactone)/gelatin electrospun nanofibers. Cholesterol esterase, mimicking the inflammation environment, is adopted to catalyze the hydrolysis of the ester bonds, both in the prodrug and the nanofibers matrix, leading to the generation of indomethacin and the subsequent release to the surrounding. In contrast, only a minor amount of the drug is released from the scaffold, just based on the mechanism of hydrolysis in the absence of cholesterol esterase. Furthermore, the inflammation-responsive nanofiber scaffold can effectively inhibit the cytokines secreted from RAW264.7 macrophage cells induced by lipopolysaccharide in vitro studies, highlighting the great potential of these electrospun nanofiber scaffolds to be applied for regulating the chronic inflammation in tissue regeneration.

Polymeric particle-based therapies for acute inflammatory diseases

Acute inflammation is essential for initiating and coordinating the body's response to injuries and infections. However, in acute inflammatory diseases, inflammation is not resolved but propagates further, which can ultimately lead to tissue damage such as in sepsis, acute respiratory distress syndrome and deep vein thrombosis. Currently, clinical protocols are limited to systemic steroidal treatments, fluids and antibiotics that focus on eradicating inflammation rather than modulating it. Strategies based on stem cell therapeutics and selective blocking of inflammatory molecules, despite showing great promise, still lack the scalability and specificity required to treat acute inflammation. By contrast, polymeric particle systems benefit from uniform manufacturing at large scales while preserving biocompatibility and versatility, thus providing an ideal platform for immune modulation. Here, we outline design aspects of polymeric particles including material, size, shape, deformability and surface modifications, providing a strategy for optimizing the targeting of acute inflammation.

Bridging micro/nano-platform and airway allergy intervention

Allergic airway diseases, with incidence augmenting visibly as industrial development and environmental degradation, are characterized by sneezing, itching, wheezing, chest tightness, airway obstruction, and hyperresponsiveness. Current medical modalities attempt to combat these symptoms mostly by small molecule chemotherapeutants, such as corticosteroids, antihistamines, etc., via intranasal approach which is one of the most noninvasive, rapid-absorbed, and patient-friendly routes. Nevertheless, inherent defects for irritation to respiratory mucosa, drug inactivation and degradation, and rapid drug dispersal to off-target sites are inevitable. Lately, intratracheal micro/nano therapeutic systems are emerging as innovative alternatives for airway allergy interventions. This overview introduces several potential application directions of mic/nano-platform in the treatment of airway allergic diseases, including carriers, therapeutic agents, and immunomodulators. The improvement of the existing drug therapy of respiratory allergy management by micro/nano-platform is described in detail. The challenges of the micro/nano-platform nasal approach in the treatment of airway allergy are summarized and the development of micro/nano-platform is also prospected. Although still a burgeoning area, micro/nano therapeutic systems are gradually turning to be realistic orientations as crucial future alternative therapeutic options in allergic airway inflammation interventions.

Redox Responsive Copolyoxalate Smart Polymers for Inflammation and Other Aging-Associated Diseases

Polyoxalate (POx) and copolyoxalate (CPOx) smart polymers are topics of interest the field of inflammation. This is due to their drug delivery ability and their potential to target reactive oxygen species (ROS) and to accommodate small molecules such as curcumin, vanilline, and p-Hydroxybenzyl alcohol. Their biocompatibility, ultra-size tunable characteristics and bioimaging features are remarkable. In this review we discuss the genesis and concept of oxylate smart polymer-based particles and a few innovative systemic delivery methods that is designed to counteract the inflammation and other aging-associated diseases (AADs). First, we introduce the ROS and its role in human physiology. Second, we discuss the polymers and methods of incorporating small molecule in oxalate backbone and its drug delivery application. Finally, we revealed some novel proof of concepts which were proven effective in disease models and discussed the challenges of oxylate polymers.

Novel drug delivery systems targeting oxidative stress in chronic obstructive pulmonary disease: a review

Oxidative stress is significantly involved in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). Combining antioxidant drugs or nutrients results in a noteworthy therapeutic value in animal models of COPD. However, the benefits have not been reproduced in clinical applications, this may be attributed to the limited absorption, concentration, and half-life of exogenous antioxidants. Therefore, novel drug delivery systems to combat oxidative stress in COPD are needed. This review presents a brief insight into the current knowledge on the role of oxidative stress and highlights the recent trends in novel drug delivery carriers that could aid in combating oxidative stress in COPD. The introduction of nanotechnology has enabled researchers to overcome several problems and improve the pharmacokinetics and bioavailability of drugs. Large porous microparticles, and porous nanoparticle-encapsulated microparticles are the most promising carriers for achieving effective pulmonary deposition of inhaled medication and obtaining controlled drug release. However, translating drug delivery systems for administration in pulmonary clinical settings is still in its initial phases.

Dexamethasone-loaded H2O2-activatable anti-inflammatory nanoparticles for on-demand therapy of inflammatory respiratory diseases

Asthma is a common airway inflammatory disorder, characterized by increased infiltration of leukocytes and bronchoconstriction. Dexamethasone (DEX) has been widely used in the treatment of allergic asthma. However, long-term and frequent use of DEX has side effects. We therefore reasoned that if drug carriers have intrinsic anti-inflammatory and anti-asthmatic activity and synergize with drug payloads, a low dose of DEX could exert sufficient therapeutic effects. In this study, we developed DEX-loaded H₂O₂-activatable boronate maltodextrin (DEX-BM) nanoparticles. DEX-BM nanoparticles released DEX in a H₂O₂-triggered manner and remarkably suppressed the expression of pro-inflammatory cytokines in activated macrophages and lung epithelial cells. In the studies of a murine allergic asthma model, DEX-BM nanoparticles (5 mg/kg) effectively inhibited the inflammatory cell infiltration and airway inflammation than equivalent DEX and BM nanoparticles without noticeable side effects. We anticipate that DEX-BM nanoparticles hold great potential as therapeutic agents for various airway inflammatory diseases.

Antioxidant Nanotherapies for the Treatment of Inflammatory Diseases

Reactive oxygen species (ROS) are essential in regulating various physiological functions. However, overproduction of ROS is implicated in the pathogenesis of various inflammatory diseases. Antioxidant therapy has thus represented an effective strategy for the treatment of oxidative stress relevant inflammatory diseases. Conventional anti-oxidative agents showed limited in vivo effects owing to their non-specific distribution and low retention in disease sites. Over the past decades, significant achievements have been made in the development of antioxidant nanotherapies that exhibit multiple advantages such as excellent pharmacokinetics, stable anti-oxidative activity, and intrinsic ROS-scavenging properties. This review provides a comprehensive overview on recent advances in antioxidant nanotherapies, including ROS-scavenging inorganic nanoparticles, organic nanoparticles with intrinsic antioxidant activity, and drug-loaded anti-oxidant nanoparticles. We highlight the biomedical applications of antioxidant nanotherapies in the treatment of different inflammatory diseases, with an emphasis on inflammatory bowel disease, cardiovascular disease, and brain diseases. Current challenges and future perspectives to promote clinical translation of antioxidant nanotherapies are also briefly discussed.

ROS-Sensitive Degradable PEG-PCL-PEG Micellar Thermogel

A reactive oxygen species (ROS)-sensitive degradable polymer would be a promising material in designing a disease-responsive system or accelerating degradation of polymers with slow hydrolysis kinetics. Here, a thermogelling poly(ethylene glycol)-polycaprolactone-poly(ethylene glycol) (PEG-PCL-PEG or EG₁₂ -CL₂₀ -EG₁₂ ) triblock copolymer with an oxalate group at the middle of the polymer is reported. The polymers form micelles with an average size of 100 nm in water. Thermogelation is observed in a concentration range of 8.0-37.0 wt%. In particular, the aqueous PEG-PCL-PEG triblock copolymer solutions are in a gel state at 37 °C in a concentration range of 25.0-37.0 wt%, whereas the aqueous PEG-PCL diblock copolymer solutions are in a sol state in the same concentration range at 37 °C. Thus, the gel depot could dissolve out once degradation of the triblock copolymers occurs at the oxalate group as confirmed by the in vitro experiment. In vivo gel formation is confirmed by injecting an aqueous PEG-PCL-PEG solution (36.0 wt%) into the subcutaneous layer of rats. The gel completely disappears in 21 d. A model polypeptide drug (cyclosporine A) is released over 21 d from the in situ formed gel. The micelle-based thermogel of PEG-PCL-PEG with ROS-triggering degradability is a promising injectable material for biomedical applications.

Recent Developments in the Reduction of Oxidative Stress through Antioxidant Polymeric Formulations

Reactive oxygen and nitrogen species (RONS) are produced endogenously in our body, or introduced through external factors, such as pollution, cigarette smoke, and excessive sunlight exposure. In normal conditions, there is a physiological balance between pro-oxidant species and antioxidant molecules that are able to counteract the detrimental effect of the former. Nevertheless, when this homeostasis is disrupted, the resulting oxidative stress can lead to several pathological conditions, from inflammation to cancer and neurodegenerative diseases. In this review, we report on the recent developments of different polymeric formulations that are able to reduce the oxidative stress, from natural extracts, to films and hydrogels, and finally to nanoparticles (NPs).

Increasing complexity and interactions of oxidative stress in chronic respiratory diseases: An emerging need for novel drug delivery systems

Oxidative stress is intensely involved in enhancing the severity of various chronic respiratory diseases (CRDs) including asthma, chronic obstructive pulmonary disease (COPD), infections and lung cancer. Even though there are various existing anti-inflammatory therapies, which are not enough to control the inflammation caused due to various contributing factors such as anti-inflammatory genes and antioxidant enzymes. This leads to an urgent need of novel drug delivery systems to combat the oxidative stress. This review gives a brief insight into the biological factors involved in causing oxidative stress, one of the emerging hallmark feature in CRDs and particularly, highlighting recent trends in various novel drug delivery carriers including microparticles, microemulsions, microspheres, nanoparticles, liposomes, dendrimers, solid lipid nanocarriers etc which can help in combating the oxidative stress in CRDs and ultimately reducing the disease burden and improving the quality of life with CRDs patients. These carriers improve the pharmacokinetics and bioavailability to the target site. However, there is an urgent need for translational studies to validate the drug delivery carriers for clinical administration in the pulmonary clinic.

pH-responsive and porous vancomycin-loaded PLGA microspheres: evidence of controlled and sustained release for localized inflammation inhibition in vitro

Adequate delivery of antibiotics to infected sites is crucial for the effective treatment of bacterial infections. A controlled and sustained release system based on porous and pH-responsive poly(lactic-co-glycolic acid) (PLGA)-vancomycin (Van) microspheres was developed. In this system, drug release is triggered by the weakly acidic environment, like local inflamed tissues. The microspheres, developed through the W1/O/W2 double-emulsion evaporation method, comprised a PLGA-based shell and a core containing Van and the bubble-generating agent of NaHCO3. The optimized preparation conditions for PLGA-NaHCO3-Van microspheres were investigated and characterized. The PLGA-NaHCO3-Van microspheres exhibited porous microstructures with regular shape and uniform size and the characteristic of controlled drug release, which could be attributed to the incorporation of NaHCO3. The results of the Kirby-Bauer assay confirmed that released Van retained effective antibacterial activity towards standard Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) infected clinical samples, suggesting their further promising application in local anti-infection.

Polyurethane Microparticles for Stimuli Response and Reduced Oxidative Degradation in Highly Porous Shape Memory Polymers

Shape memory polymers (SMPs) have been found to be promising biomaterials for a variety of medical applications; however, the clinical translation of such technology is dependent on tailorable properties such as gravimetric changes in degradation environments. For SMPs synthesized from amino-alcohols, oxidation resulting in rapid mass loss may be problematic in terms of loss of material functionality as well as toxicity and cytocompatibility concerns. Control of gravimetric changes was achieved through the incorporation of small molecule antioxidants, either directly into the polymer matrix or included in microparticles to form a SMP composite material. With direct incorporation of small molecule phenolic antioxidant 2,2'-methylenebis(6- tert-butyl)-methylphenol (Methyl), SMPs displayed reduce strain recovery by more than 50% (Methyl) and increase elastic modulus from approximately 1.4 to 2.3 MPa, at the expense of the strain to failure being reduced from 45% to 32%. Importantly, such changes could not ensure retention of the antioxidants and therefore did not increase oxidative stability beyond 15 days in accelerated oxidative conditions (equivalent to approximately 800 days in porcine aneurysms) in all cases except for the inclusion of a hindered amine that capped network growth, which also resulted in shape memory reduction (only 80% recoverable strain achieved). However, the inclusion of antioxidants in microparticles was found to produce materials with similar thermomechanical ( T_g migration below 1.0 °C) and shape recovery of 100%, while increasing oxidative resistance compared to controls (oxidation onset was delayed by 3 days and material lifespan increased to approximately 20-22 days in accelerated oxidative solution or beyond 1000 days in the porcine aneurysm). The microparticle composite SMPs also act as a platform for environmental sensing, such as pH-dependent fluorescence shifts and payload release, as demonstrated by fluorescent dye studies using phloxine B and nile blue chloride and the release of antioxidants over a 3 week period. The use of polyurethane-urea microparticles in porous SMPs is demonstrated to increase biostability of the materials, by approximately 25%, and ultimately extend their lifespan for use in aneurysm occlusion as determined through calculated in vivo degradation rates corresponding to a porcine aneurysm environment.

Ultrasound imaging and on-demand therapy of peripheral arterial diseases using H2O2-Activated bubble generating anti-inflammatory polymer particles

Muscles of peripheral artery disease (PAD) patients are under oxidative stress associated with a significantly elevated level of reactive oxygen species (ROS) including hydrogen peroxide (H₂O₂). Curcumin is a major active constituent of turmeric and is well known for its highly potent antioxidant, anti-inflammatory and angiogenic effects. We previously reported antioxidant vanillyl alcohol-incorporated copolyoxalate (PVAX) which is designed to rapidly scavenge H₂O₂ and release bioactive vanillyl alcohol and CO₂ in a H₂O₂-triggered manner. In this work, we developed curcumin-loaded PVAX (CUR-PVAX) nanoparticles as contrast-enhanced ultrasound imaging agents as well as on-demand therapeutic agents for ischemic injuries based on the hypothesis that PVAX nanoparticles generate echogenic CO₂ bubbles through H₂O₂-triggered oxidation of peroxalate esters and the merger of curcumin and PVAX exerts H₂O₂-activatable synergistic therapeutic actions. CUR-PVAX nanoparticles also displayed the drastic ultrasound signal in ischemic areas by generating CO₂ bubbles. CUR-PVAX nanoparticles exhibited significantly higher antioxidant and anti-inflammatory activities than empty PVAX nanoparticles and equivalent curcumin in vascular endothelial cells. A mouse model of ischemic injury was used to evaluate the potential of CUR-PVAX nanoparticles as ultrasound imaging agents and on-demand therapeutic agents. CUR-PVAX nanoparticles significantly suppressed the expression of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β). Moreover, CUR-PVAX nanoparticles significantly enhanced the level of vascular endothelial growth factor (VEGF) and platelet endothelial cell adhesion molecule-1 (PECAM-1, also known as CD31), leading to blood perfusion into ischemic tissues. We, therefore, believe that CUR-PVAX nanoparticles hold great translational potential as novel theranostic agents for ischemic diseases such as PAD.

Oligochitosan-stabilized photoluminescent gold nanoconstructs for optical bioimaging

Background

Gold nanoclusters (AuNCs) are typically composed of several to tens of gold atoms which are stabilized with biomacromolecules such as bovine serum albumin (BSA). Au NCs fluoresces in the visible to near infrared region, in a size-dependent manner. AuNCs solutions have potential as fluorophore in a wide range of biomedical applications such as biodetection, biosensing and bioimaging in vitro and in vivo. However, their stability and harsh condition of preparation limit their biomedical application.

Methods

BSA stabilized AuNCs (BSA-AuNCs) were prepared by mixing HAuCl₄ solution with BSA solution for 24 h at 37°C under basic condition. BSA-AuNCs were then mixed with oliogochitosan (OCS) to generate BSA-Au-OCS nanocomplexes. The physicochemical and optical properties of BSA-Au-OCS nanocomplexes were studied using a fluorospectrometer. Their potential as a bioimaging agent in vivo and in vitro was evaluated using a fluorescent imaging instrument.

Results

BSA-stabilized AuNCs solutions were mixed with oligochitosan (OCS) to develop BSA-Au-OCS nanocomplexes of a mean diameter of ~250 nm. BSA-Au-OCS nanocomplexes could emit light at 620 nm and the complexation with OCS did not affect the photophysical properties of BSA-AuNCs. BSA-Au-OCS nanocomplexes showed less cytotoxicity than BSA-AuNCs and was readily taken up by cells. BSA-Au-OCS nanocomplexes showed strong fluorescence in tissues.

Conclusions

We developed stable BSA-Au-OCS nanocomplexes which fluoresce in the near infrared region. BSA-Au-OCS nanocomplexes exhibited significantly less cytotoxicity and strong fluorescence emission, suggesting potential for biomedical applications.

Ultrasonographic Imaging and Anti-inflammatory Therapy of Muscle and Tendon Injuries Using Polymer Nanoparticles

Ultrasonography is a reliable diagnostic modality for muscle and tendon injuries, but it has been challenging to find right diagnosis of minor musculoskeletal injuries by conventional ultrasonographic imaging. A large amount of hydrogen peroxide (H2O2) are known to be generated during tissue damages such as mechanical injury and therefore H2O2 holds great potential as a diagnostic and therapeutic marker for mechanical injuries in the musculoskeletal system. We previously developed poly(vanillyl alcohol-co-oxalate) (PVAX), which rapidly scavenges H2O2 and exerts antioxidant and anti-inflammatory activity in H2O2-associated diseases. Based on the notion that PVAX nanoparticles generate CO2 bubbles through H2O2-triggered hydrolysis, we postulated that PVAX nanoparticles could serve as ultrasonographic contrast agents and therapeutic agents for musculoskeletal injuries associated with overproduction of H2O2. In the agarose gel phantom study, PVAX nanoparticles continuously generated CO2 bubbles to enhance ultrasonographic echogenicity significantly. Contusion injury significantly elevated the level of H2O2 in skeletal muscles and Achilles tendons. Upon intramuscular injection, PVAX nanoparticles significantly elevated the ultrasound contrast and suppressed inflammation and apoptosis in the contusion injury of musculoskeletal systems. We anticipate that PVAX nanoparticles hold great translational potential as theranostic agents for musculoskeletal injuries.

Advance of antioxidants in asthma treatment

Asthma is an allergic disease, characterized as a recurrent airflow limitation, airway hyperreactivity, and chronic inflammation, involving a variety of cells and cytokines. Reactive oxygen species have been proven to play an important role in asthma. The pathogenesis of oxidative stress in asthma involves an imbalance between oxidant and antioxidant systems that is caused by environment pollutants or endogenous reactive oxygen species from inflammation cells. There is growing evidence that antioxidant treatments that include vitamins and food supplements have been shown to ameliorate this oxidative stress while improving the symptoms and decreasing the severity of asthma. In this review, we summarize recent studies that are related to the mechanisms and biomarkers of oxidative stress, antioxidant treatments in asthma.

Oxidative Stress and Bronchial Asthma in Children-Causes or Consequences?

Bronchial asthma is one of the most common chronic inflammatory diseases of the airways. In the pathogenesis of this disease, the interplay among the genes, intrinsic, and extrinsic factors are crucial. Various combinations of the involved factors determine and modify the final clinical phenotype/endotype of asthma. Oxidative stress results from an imbalance between the production of reactive oxygen species and reactive nitrogen species and the capacity of antioxidant defense mechanisms. It was shown that oxidative damage of biomolecules is strongly involved in the asthmatic inflammation. It is evident that asthma is accompanied by oxidative stress in the airways and in the systemic circulation. The oxidative stress is more pronounced during the acute exacerbation or allergen challenge. On the other hand, the genetic variations in the genes for anti-oxidative and pro-oxidative enzymes are variably associated with various asthmatic subtypes. Whether oxidative stress is the consequence of, or the cause for, chronic changes in asthmatic airways is still being discussed. Contribution of oxidative stress to asthma pathology remains at least partially controversial, since antioxidant interventions have proven rather unsuccessful. According to current knowledge, the relationship between oxidative stress and asthmatic inflammation is bidirectional, and genetic predisposition could modify the balance between these two positions-oxidative stress as a cause for or consequence of asthmatic inflammation.

One-pot synthesis of reactive oxygen species (ROS)-self-immolative polyoxalate prodrug nanoparticles for hormone dependent cancer therapy with minimized side effects

One-pot synthesis of ROS-self-immolative polyoxalate prodrug NPs for cancer therapy.

Physicochemical properties and biocompatibility of PZL/PLGA/bioglass composite scaffolds for bone tissue engineering

Foamy poly(N_ε-Cbz-l-lysine)/poly(lactic-co-glycolic acid)/bioglass composite scaffolds had appropriate physicochemical properties, good biomineralization ability, excellent cytocompatibility and histocompatibility, and desirable osteogenic ability.