Strategies for surface modification of gelatin-based nanoparticles

Development and functional evaluation of a hyaluronic acid coated nano-formulation with kaempferol as a novel intra-articular agent for Knee Osteoarthritis treatment

Knee osteoarthritis (OA) involves articular cartilage degradation driven mainly by inflammation. Kaempferol (KM), known for its anti-inflammatory property, holds potential for OA treatment. This study investigated the potential of hyaluronic acid (HA)-coated gelatin nanoparticles loaded with KM (HA-KM GNP) for treating knee OA. KM was encapsulated into gelatin nanoparticles (KM GNP) and then coated with HA to form HA-KM GNPs. Physical properties were characterized, and biocompatibility and cellular uptake were assessed in rat chondrocytes. Anti-inflammatory and chondrogenic properties were evaluated using IL-1β-stimulated rat chondrocytes, compared with HA-coated nanoparticles without KM (HA GNP) and KM alone. Preclinical efficacy was tested in an anterior cruciate ligament transection (ACLT)-induced knee OA rat model treated with intra-articular injection of HA-KM GNP. Results show spherical HA-KM GNPs (88.62 ± 3.90 nm) with positive surface charge. Encapsulation efficiency was 98.34 % with a sustained release rate of 18 % over 48 h. Non-toxic KM concentration was 2.5 μg/mL. In IL-1β-stimulated OA rat chondrocytes, HA-KM GNP significantly down-regulated RNA expression of IL-1β, TNF-α, COX-2, MMP-9, and MMP-13, while up-regulating SOX9 compared to HA GNP, and KM. In vivo imaging demonstrated significantly higher fluorescence intensity within rat knee joints for 3 hours post HA-KM GNP injection compared with KM GNP (185.2% ± 34.1% vs. 45.0% ± 16.7%). HA-KM GNP demonstrated significant effectiveness in reducing subchondral sclerosis, attenuating inflammation, inhibiting matrix degradation, restoring cartilage thickness, and reducing the severity of OA in the ACLT rat model. In conclusion, HA-KM GNP holds promise for knee OA therapy.

Application of Bioactive Materials for Osteogenic Function in Bone Tissue Engineering

Bone tissue defects present a major challenge in orthopedic surgery. Bone tissue engineering using multiple versatile bioactive materials is a potential strategy for bone-defect repair and regeneration. Due to their unique physicochemical and mechanical properties, biofunctional materials can enhance cellular adhesion, proliferation, and osteogenic differentiation, thereby supporting and stimulating the formation of new bone tissue. 3D bioprinting and physical stimuli-responsive strategies have been employed in various studies on bone regeneration for the fabrication of desired multifunctional biomaterials with integrated bone tissue repair and regeneration properties. In this review, biomaterials applied to bone tissue engineering, emerging 3D bioprinting techniques, and physical stimuli-responsive strategies for the rational manufacturing of novel biomaterials with bone therapeutic and regenerative functions are summarized. Furthermore, the impact of biomaterials on the osteogenic differentiation of stem cells and the potential pathways associated with biomaterial-induced osteogenesis are discussed.

Multilayer nanodrug delivery system with spatiotemporal drug release improves tumor microenvironment for synergistic anticancer therapy

The inflammatory response is one of the general symptoms that accompany tumorigenesis, the pro-inflammatory factors cyclooxygenase-2 (COX-2) and COX-2-derived prostaglandin-2 (PGE-2) in the inflammatory environment surrounding tumors possess promoting tumor development, metastasis and angiogenesis effects. In addition, the hypoxic environment of tumors severely limits the effectiveness of photodynamic therapy (PDT). In this study, a universal extracellular-intracellular 'on-demand' release nanomedicine DOX@PDA-ICG@MnO2@GN-CEL was developed for the combined fight against malignant tumors using a spatiotemporal controlled gelatin coated polydopamine (PDA@GN) as the carrier and loaded with the chemotherapeutic drug doxorubicin (DOX), the photosensitizer indocyanine green (ICG), the PDT enhancer MnO2and the anti-inflammatory drug celecoxib (CEL) individually. Our results showed that DOX@PDA-ICG@MnO2@GN-CEL could release CEL extracellularly by matrix metalloproteinase-2 response and inhibit the COX-2/PGE-2 pathway, reduce chemotherapy resistance and attenuate the concurrent inflammation. After entering the tumor cells, the remaining DOX@PDA-ICG@MnO2released DOX, ICG and MnO2intracellularly through PDA acid response. MnO2promoted the degradation of endogenous H2O2to generate oxygen under acidic conditions to alleviate the tumor hypoxic environment, enhance PDT triggered by ICG. PDA and ICG exhibited photothermal therapy synergistically, and DOX exerted chemotherapy with reduced chemotherapy resistance. The dual responsive drug release switch enabled the chemotherapeutic, photothermal, photodynamic and anti-inflammatory drugs precisely acted on different sites of tumor tissues and realized a promising multimodal combination therapy.

MMP-Responsive Nanoparticle-Loaded, Injectable, Adhesive, Self-Healing Hydrogel Wound Dressing Based on Dynamic Covalent Bonds

Developing a multifunctional hydrogel wound dressing with good injectability, self-healing, tissue adhesion, biocompatibility, and fast skin wound healing efficiency remains challenging. In this work, an injectable adhesive dopamine-functionalized oxidized hyaluronic acid/carboxymethyl chitosan/collagen (AHADA/CCS/Col) hydrogel was constructed. The Schiff dynamic bond between AHADA and CCS, the N-Ag-N bond between CCS and Ag ions, and the S-Ag-S dynamic bond between sulfhydryl-modified collagen (ColSH) and Ag ions allowed the hydrogel to be both injectable and self-healing. Moreover, the aldehyde groups and catechol groups presented in the hydrogel could generate force with several groups on the tissue interface; therefore, the hydrogel also had good tissue adhesion. In vitro experiments proved that this hydrogel exhibited good biocompatibility and could promote cell proliferation. Additionally, curcumin (Cur)-loaded gelatin nanoparticles (Cur@Gel NPs) were prepared, which could respond to matrix metalloproteinases (MMPs) and controllably release Cur to hasten wound healing efficiency. Animal experiment results showed that this AHADA/CCS/Col hydrogel loaded with Cur@Gel NPs promoted wound repairing better, indicating its potential as a wound dressing.

Drug Delivery of Gelatin Nanoparticles as a Biodegradable Polymer for the Treatment of Infectious Diseases: Perspectives and Challenges

In recent years, there has been a growing interest in the use of gelatin nanoparticles (GNPs) for the treatment of infectious diseases. The inherent properties of these nanoparticles make them attractive options for drug delivery. Their biocompatibility ensures that they can interact with biological systems without causing adverse reactions, while their biodegradability ensures that they can break down harmlessly in the body once their function is performed. Furthermore, their capacity for controlled drug release ensures that therapeutic agents can be delivered over a sustained period, thereby enhancing treatment efficacy. This review examines the current landscape of GNP-based drug delivery, with a specific focus on its potential applications and challenges in the context of infectious diseases. Key challenges include controlling drug release rates, ensuring nanoparticle stability under physiological conditions, scaling up production while maintaining quality, mitigating potential immunogenic reactions, optimizing drug loading efficiency, and tracking the biodistribution and clearance of GNPs in the body. Despite these hurdles, GNPs hold promising potential in the realm of infectious disease treatment. Ongoing research and innovation are essential to overcome these obstacles and completely harness the potential of GNPs in clinical applications.

Structural and functional insights in polysaccharides coated cerium oxide nanoparticles and their potential biomedical applications: A review

Cerium oxide nanoparticles have now significant presence in biomedical fields due to their wide applications; however, challenges regarding their safety and biocompatibility persist. Polysaccharides based biopolymers have inherent hydroxyl and carboxyl groups, enabling them to govern the surface functionalization of cerium oxide nanoparticles, hence their chemical and physical characteristics. Because of this, polysaccharides such as dextran, alginate, pullulan, chitosan, polylactic acid, starch, and pectin are practical substitutes for the conventional coatings used to synthesize cerium oxide nanoparticles. This review discusses the effect of biopolymer coatings on the properties of cerium oxide nanoparticles, such as size, stability, aggregation, and biocompatibility. Additionally, it also summarises various biomedical applications of polysaccharides coated cerium oxide nanoparticles, such as in bone tissue regeneration, liver inflammation, wound healing, and antibacterial and anticancer activities. Biocompatible cerium oxide nanoparticles will surely improve their applications in the biomedical field.

Complex Modification Orders Alleviate the Gelling Weakening Behavior of High Microbial Transglutaminase (MTGase)-Catalyzed Fish Gelatin: Gelling and Structural Analysis

In this paper, the effects of different modification orders of microbial transglutaminase (MTGase) and contents of pectin (0.1-0.5%, w/v) on the gelling and structural properties of fish gelatin (FG) and the modification mechanism were studied. The results showed that the addition of pectin could overcome the phenomenon of high-MTGase-induced lower gelling strength of gelatin gels. At a low pectin content, the modification sequences had non-significant influence on the gelling properties of modified FG, but at a higher pectin content (0.5%, w/v), P0.5%-FG-TG had higher gel strength (751.99 ± 10.9 g) and hardness (14.91 ± 0.33 N) values than those of TG-FG-P0.5% (687.67 ± 20.98 g, 12.18 ± 0.45 N). Rheology analysis showed that the addition of pectin normally improved the gelation points and melting points of FG. The structural results showed that the fluorescence intensity of FG was decreased with the increase in pectin concentration. Fourier transform infrared spectroscopy analysis indicated that the MTGase and pectin complex modifications could influence the secondary structure of FG, but the influenced mechanisms were different. FG was firstly modified by MTGase, and then pectin (P-FG-TG) had the higher gelling and stability properties.

Current Trends in Gelatin-Based Drug Delivery Systems

Gelatin is a highly versatile natural polymer, which is widely used in healthcare-related sectors due to its advantageous properties, such as biocompatibility, biodegradability, low-cost, and the availability of exposed chemical groups. In the biomedical field, gelatin is used also as a biomaterial for the development of drug delivery systems (DDSs) due to its applicability to several synthesis techniques. In this review, after a brief overview of its chemical and physical properties, the focus is placed on the commonly used techniques for the development of gelatin-based micro- or nano-sized DDSs. We highlight the potential of gelatin as a carrier of many types of bioactive compounds and its ability to tune and control select drugs' release kinetics. The desolvation, nanoprecipitation, coacervation, emulsion, electrospray, and spray drying techniques are described from a methodological and mechanistic point of view, with a careful analysis of the effects of the main variable parameters on the DDSs' properties. Lastly, the outcomes of preclinical and clinical studies involving gelatin-based DDSs are thoroughly discussed.

Dual size/charge-switchable and multi-responsive gelatin-based nanocluster for targeted anti-tumor therapy

Biopolymers with excellent biocompatibility and biodegradability show great potential for designing drug nanocarriers, while it's difficult to fabricate smart vehicles with multiple switching (size, surface, shape) based on biopolymers alone. Here, we report a dual size/charge-switchable and multi-responsive doxorubicin-loaded gelatin-based nanocluster (DOX-icluster) for improved tumor penetration and targeted anti-tumor therapy. The DOX-icluster was electrostatically assembled from folic acid and dimethylmaleic anhydride modified gelatin (FA-GelDMA) and small-sized DOX-loaded NH₂ modified hollow mesoporous organosilicon nanoparticles (DOX-HMON-NH₂). DOX-icluster had an initial size of about 199 nm at neutral pH. After accumulation in tumor tissue, the DMA bond of FA-GelDMA was cleaved and gelatin was degraded by matrix metalloproteinase (MMP-2), thus 48 nm and positively charged DOX-HMON-NH₂ was released to facilitate penetration and cell internalization. DOX-HMON-NH₂ was further degraded by intracellular glutathione (GSH) with releasing 48.1 % of DOX. The cellular uptake results indicated that the fabricated icluster promoted the uptake of DOX by 4T1 cells. With enhanced penetration efficacy, the tumor spheroids volume treated with DOX-icluster was reduced to 15.1 % on day 7. This cytocompatible multi-responsive gelatin-based icluster with size-shrinking and charge-reversible characteristics may be used as a significant drug carrier for tumor therapy.

Gelatin as It Is: History and Modernity

The data concerning the synthesis and physicochemical characteristics of one of the practically important proteins-gelatin, as well as the possibilities of its practical application, are systematized and discussed. When considering the latter, emphasis is placed on the use of gelatin in those areas of science and technology that are associated with the specifics of the spatial/molecular structure of this high-molecular compound, namely, as a binder for the silver halide photographic process, immobilized matrix systems with a nano-level organization of an immobilized substance, matrices for creating pharmaceutical/dosage forms and protein-based nanosystems. It was concluded that the use of this protein is promising in the future.

Controlled Cascade-Release and High Selective Sterilization by Core-Shell Nanogels for Microenvironment Regulation of Aerobic Vaginitis

Aerobic vaginitis (AV) is a gynecological disease associated with vaginal flora imbalance. The nonselective bactericidal nature of antibiotics and low customization rate of probiotic supplementation in existing treatments lead to AV recurrence. Here, a drug delivery strategy is proposed that works with the changing dynamics of the bacterial flora. In particular, a core-shell nanogel (CSNG) is designed to encapsulate prebiotic inulin and antimicrobial peptide Cath 30. The proposed strategy allows for the sequential release of both drugs using gelatinase produced by AV pathogenic bacteria, initially selectively killing pathogenic bacteria and subsequently promoting the proliferation of beneficial bacteria in the vagina. In a simulated infection environment in vitro, the outer layer of CSNGs, Cath 30 is rapidly degraded and potently killed the pathogenic bacterium Staphylococcus aureus at 2-6 h. CSNGs enhances proliferation of the beneficial bacterium Lactobacillus crispatus by more than 50% at 24 h. In a rat AV model, the drug delivery strategy precisely regulated the bacterial microenvironment while controlling the inflammatory response of the vaginal microenvironment. This new treatment approach, configured on demand and precisely controlled, offers a new strategy for the treatment of vaginal diseases.

The Effect of Elasticity of Gelatin Nanoparticles on the Interaction with Macrophages

Gelatin is a biocompatible, biodegradable, cheap, and nontoxic material, which is already used for pharmaceutical applications. Nanoparticles from gelatin (GNPs) are considered a promising delivery system for hydrophilic and macromolecular drugs. Mechanical properties of particles are recognized as an important parameter affecting drug carrier interaction with biological systems. GNPs offer the preparation of particles with different stiffness. GNPs were loaded with Fluorescein isothiocyanate-labeled 150 kDa dextran (FITC-dextran) yielding also different elastic properties. GNPs were visualized using atomic force microscopy (AFM), and force-distance curves from the center of the particles were evaluated for Young's modulus calculation. The prepared GNPs have Young's moduli from 4.12 MPa for soft to 9.8 MPa for stiff particles. Furthermore, cytokine release (IL-6 and TNF-α), cell viability, and cell uptake were determined on macrophage cell lines from mouse (RAW 264.7) and human (dTHP-1 cells, differentiated human monocytic THP-1 cells) origin for soft and stiff GNPs. Both particle types showed good cell compatibility and did not induce IL-6 and TNF-α release from RAW 264.7 and dTHP-1 cells. Stiffer GNPs were internalized into cells faster and to a larger extent.

Nanocarrier-Based Drug Delivery to Brain: Interventions of Surface Modification

Brain disorders are a prevalent and rapidly growing problem in the medical field as they adversely affect the quality of life of a human. With an increase in life expectancy, it has been reported that diseases like Alzheimer's, Parkinson's, stroke and brain tumors, along with neuropsychological disorders, are also being reported at an alarmingly high rate. Despite various therapeutic methods for treating brain disorders, drug delivery to the brain has been challenging because of a very complex Blood Brain Barrier, which precludes most drugs from entering the brain in effective concentrations. Nano-carrier-based drug delivery systems have been reported widely by researchers to overcome this barrier layer. These systems due to their small size, offer numerous advantages; however, their short residence time in the body owing to opsonization hinders their success in vivo. This review article focuses on the various aspects of modifying the surfaces of these nano-carriers with polymers, surfactants, protein, antibodies, cell-penetrating peptides, integrin binding peptides and glycoproteins such as transferrin & lactoferrin leading to enhanced residence time, desirable characteristics such as the ability to cross the blood-brain barrier (BBB), increased bioavailability in regions of the brain and targeted drug delivery.

Branched Poly(ε-caprolactone)-Based Copolyesters of Different Architectures and Their Use in the Preparation of Anticancer Drug-Loaded Nanoparticles

Limitations associated with the use of linear biodegradable polyesters in the preparation of anticancer nano-based drug delivery systems (nanoDDS) have turned scientific attention to the utilization of branched-chain (co-)polymers. In this context, the present study evaluates the use of novel branched poly(ε-caprolactone) (PCL)-based copolymers of different architectures for the preparation of anticancer nanoparticle (NP)-based formulations, using paclitaxel (PTX) as a model drug. Specifically, three PCL-polyol branched polyesters, namely, a three-arm copolymer based on glycerol (PCL-GLY), a four-arm copolymer based on pentaerythritol (PCL-PE), and a five-arm copolymer based on xylitol (PCL-XYL), were synthesized via ring-opening polymerization and characterized by proton nuclear magnetic resonance (¹H-NMR), gel permeation chromatography (GPC), intrinsic viscosity, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy and cytotoxicity. Then, PTX-loaded NPs were prepared by an oil-in-water emulsion. The size of the obtained NPs varied from 200 to 300 nm, while the drug was dispersed in crystalline form in all formulations. High encapsulation efficiency and high yields were obtained in all cases, while FTIR analysis showed no molecular drug polymer. Finally, in vitro drug release studies showed that the studied nanocarriers significantly enhanced the dissolution rate and extent of the drug.

Degradable microneedle patches loaded with antibacterial gelatin nanoparticles to treat staphylococcal infection-induced chronic wounds

Infection-induced chronic wounds cause prolonged pains, a high risk of amputation, and even increased mortality in immunocompromised patients. Here we report an antibacterial microneedle (MN) patch, which features high degradability in biological fluids and gelatinase-responsive release of an antibacterial photothermal peptide AMP-Cypate. We first synthesize gelatin nanoparticles (GNPs) and then conjugate the AMP-Cypate to afford composite AMP-Cypate@GNPs. The proteinaceous nanoparticles can responsively release AMP-Cypate in the presence of gelatinase, an enzyme secreted specifically by Staphylococcus aureus (S. aureus). AMP-Cypate@GNPs were then deposited in the tips of MNs fabricated by PVP and recombinant human type III collagen (Col III) to devise the antibacterial MN/AMP-Cypate@GNP patches. When applied to the infection site, MNs break through the epidermis and the stratum corneum, dissolve in the infected dermis, reach the bacterial colony or biofilm, release AMP-Cypate@GNPs, and exert a gelatinase-responsive photothermal therapy under near-infrared (NIR) irradiation to kill the pathogen S. aureus. In a rat model of staphylococcal infection-induced chronic wounds mimicking the condition of diabetic foot ulcer, the antibacterial MN/AMP-Cypate@GNP patches eradiated the bacterial infection and resulted in complete healing of the wounds, proving its potential application in the treatment of chronic wound infections and diabetic foot ulcers.

Pulsatile Controlled Release and Stability Evaluation of Polymeric Particles Containing Piper nigrum Essential Oil and Preservatives

Considerable efforts have been spent on environmentally friendly particles for the encapsulation of essential oils. Polymeric particles were developed to encapsulate the essential oil from Piper nigrum based on gelatin and poly-ε-caprolactone (PCL) carriers. Gas Chromatography ((Flame Ionization Detection (GC/FID) and Mass Spectrometry (GC/MS)), Atomic Force Microscopy (AFM), Nanoparticle Tracking Analysis (NTA), Confocal Laser Scanning Microscopy (CLSM), Attenuated Total Reflectance-Fourier-transform Infrared Spectroscopy (ATR-FTIR), and Ultraviolet-Visible (UV-VIS) spectroscopy were used for the full colloidal system characterization. The essential oil was mainly composed of β-caryophyllene (~35%). The stability of the encapsulated systems was evaluated by Encapsulation Efficiency (EE%), electrical conductivity, turbidity, pH, and organoleptic properties (color and odor) after adding different preservatives. The mixture of phenoxyethanol/isotialzoni-3-one (PNE system) resulted in enhanced stability of approximately 120 and 210 days under constant handling and shelf-life tests, respectively. The developed polymeric system presented a similar controlled release in acidic, neutral, or basic pH, and the release curves suggested a pulsatile release mechanism due to a complexation of essential oil in the PCL matrix. Our results showed that the developed system has potential as an alternative stable product and as a controlling agent, due to the pronounced bioactivity of the encapsulated essential oil.

Effect of carbon numbers and structures of monosaccharides on the glycosylation and emulsion stabilization ability of gelatin

Herein, the effect of saccharide glycosylation by nine monosaccharides on bovine bone gelatin for the stabilization of fish oil-loaded emulsions was explored. The gelatin modification was analyzed and then the emulsifying properties of monosaccharide-modified gelatins were analyzed at pH 9.0 and 3.0. The results demonstrated that glycosylated gelatin structure, droplet stability, creaming stability, and liquid-gel transition time were dependent on monosaccharide carbon numbers, monosaccharide structures, and solution pH. Glycosylation modification of gelatins did not obviously change the emulsion droplet stability at pH 9.0, whereas it increased the emulsion droplet stability at pH 3.0. Glycosylation modification of gelatins did not obviously change the emulsion creaming index values (5.1%-8.4% at pH 9.0 and 25.8%-33.1% at pH 3.0). Three-carbon and four-carbon monosaccharides glycosylation significantly increased emulsion liquid-gel transition times. This work provided useful information to understand the effects of carbon numbers and structures of monosaccharides on the protein modification.

Gelatin Coating for the Improvement of Stability and Cell Uptake of Hydrophobic Drug-Containing Liposomes

Purpose: Most therapeutic agents have limitations owing to low selectivity and poor solubility, resulting in post-treatment side effects. Therefore, there is a need to improve solubility and develop new formulations to deliver therapeutic agents specifically to the target site. Gelatin is a natural protein that is composed of several amino acids. Previous studies revealed that gelatin contains arginyl-glycyl-aspartic acid (RGD) sequences that become ligands for the integrin receptors expressed on cancer cells. Thus, in this study, we aimed to increase the efficiency of drug delivery into cancer cells by coating drug-encapsulating liposomes with gelatin (gelatin-coated liposomes, GCLs). Methods: Liposomes were coated with gelatin using electrostatic interaction and covalent bonding. GCLs were compared with PEGylated liposomes in terms of their size, zeta potential, encapsulation efficiency, stability, dissolution profile, and cell uptake. Results: Small-sized and physically stable GCLs were prepared, and they showed high drug-encapsulation efficiency. An in vitro dissolution study showed sustained release depending on the degree of gelatin coating. Cell uptake studies showed that GCLs were superior to PEGylated liposomes in terms of cancer cell-targeting ability. Conclusions: GCLs can be a novel and promising carrier system for targeted anticancer agent delivery. GCLs, which exhibited various characteristics depending on the coating degree, could be utilized in various ways in future studies.

ROS-responsive dimeric prodrug-based nanomedicine targeted therapy for gastric cancer

Gastric cancer (GC) remains a major public health problem. Ursolic acid (UA) is reported to be effective in inhibiting GC; however, its low solubility and poor biocompatibility have greatly hindered its clinical application. Herein, an innovative reactive oxygen species (ROS)-sensitive UA dimeric prodrug is developed by coupling two UA molecules via a ROS-cleavable linkage, which can self-assemble into stable nanoparticles in the presence of surfactant. This new UA-based delivery system comprises the following major components: (I) dimeric prodrug inner core that can achieve high drug-loading (55%, w/w) and undergo rapid and selective conversion into intact drug molecules in response to ROS; (II) a polyethylene glycol (PEG) shell to improve colloid stability and extend blood circulation, and (III) surface-modified internalizing RGD (iRGD) to increase tumor targeting. Enhancement of the antitumor effect of this delivery system was demonstrated against GC tumors in vitro and in vivo. This novel approach offers the potential for clinical applications of UA.

Design of a Nasal Spray Based on Cardiospermum halicacabum Extract Loaded in Phospholipid Vesicles Enriched with Gelatin or Chondroitin Sulfate

The extract of Cardiospermum halicacabum L. (C. halicacabum) obtained from flower, leaf and vine was loaded into modified phospholipid vesicles aiming at obtaining sprayable, biocompatible and effective nasal spray formulations for the treatment of nasopharyngeal diseases. Penetration enhancer-containing vesicles (PEVs) and hyalurosomes were formulated, and stabilized by adding a commercial gelatin from fish (20 mg/mL) or chondroitin sulfate from catshark cartilages (Scyliorhinus canicula, 20 mg/mL). Cryo-TEM images confirmed the formation of spherical vesicles, while photon correlation spectroscopy analysis disclosed the formation of small and negatively-charged vesicles. PEVs were the smaller vesicles (~100 nm) along with gelatin-hyalurosomes (~120 nm), while chondroitin-PEVs and chondroitin-hyalurosomes were larger (~160 nm). Dispersions prepared with chondroitin sulfate were more homogeneous, as the polydispersity index was ~0.15. The in vitro analysis of the droplet size distribution, average velocity module and spray cone angle suggested a good spray-ability and deposition of formulations in the nasal cavity, as the mean diameter of the droplets was in the range recommended by the Food and Drug Administration for nasal targets. The spray plume analysis confirmed the ability of PEVs, gelatin-PEVs, hyalurosomes and gelatin-hyalurosomes to be atomized in fine droplets homogenously distributed in a full cone plume, with an angle ranging from 25 to 30°. Moreover, vesicles were highly biocompatible and capable of protecting the epithelial cells against oxidative damage, thus preventing the inflammatory state.

Surface modifications to enhance osseointegration-Resulting material properties and biological responses

As life expectancy and the age of the general population increases so does the need for improved implants. A major contributor to the failure of implants is poor osseointegration, which is typically described as the direct connection between bone and implant. This leads to unnecessary complications and an increased burden on the patient population. Modification of the implant surfaces through novel techniques, such as varying topography and/or applying coatings, has become a popular method to enhance the osseointegration capability of implants. Recent research has shown that particular surface features influence how bone cells interact with a material; however, it is unknown which exact features achieve optimal bone integration. In this review, current methods of modifying surfaces will be highlighted, and the resulting surface characteristics and biological responses are discussed. Review of the current strategies of surface modifications found that many coating types are more advantageous when used in combination; however, finding a surface modification that utilizes the mutual beneficial effects of important surface characteristics while still maintaining commercial viability is where future challenges exist.

Natural polymeric nanocarriers in malignant glioma drug delivery and targeting

Among all central nervous diseases, malignant glioma is a crucial part that deserves more attention since high fatality and disability rate. There are several therapeutic strategies applied to the treatment of malignant glioma, especially certain chemotherapy-related treatments. However, the existence of the blood-brain barrier (BBB) seriously hinders the strategy's progress, so how to escape from the barriers is a fascinating question. Herein, we comprehensively discussed the details of malignant glioma and the BBB's functional morphology and summarized several routes bypassing the BBB. Additionally, since possessing excellent properties for drug delivery, we provided an insight into various promising natural polymeric materials and highlighted their applications in the treatment of malignant glioma.

A pH-controlled one-pot synthesis of gold nanostars by using a zwitterionic protein hydrolysate (gelatin): an enhanced radiosensitization of cancer cells

One-pot green synthesis of gold nanoparticles of desired shapes is developed by using FDA approved and economic GRAS materials. The gold nanoparticles exhibit radio-sensitization in A549 cells with star shaped nanoparticles showing maximum efficacy.

Size-transformable nanohybrids with pH/redox/enzymatic sensitivity for anticancer therapy

A lack of sufficient tumor penetration and low delivery efficiency are the main reasons for the limited clinical applications of nanocarriers in cancer treatment. Tumor microenvironment responsive drug delivery systems have been attracting great interest in cancer therapy as the desired drug release can be achieved in the disease sites for optimal treatment efficiency. In this work, we developed a biodegradable nanohybrid drug delivery system with pH/redox/enzymatic sensitivity by the simple assembly of bovine serum albumin nano-units (about 5 nm) onto graphene oxide nanosheets in the presence of a naturally originating protein (gelatin). The nanoparticles can maintain a constant size under physiological conditions, while releasing 5 nm nano-units containing the drug upon triggering by the environment-mimicking protease highly expressed in the tumor microenvironment. Furthermore, after reaching the tumor tissue, the acidic, reductive, and enzymatic microenvironments turned on the switch for DOX release, and the combination of chemotherapy and photothermal therapy was achieved under the trigger of near-infrared light. The nanosystems have the potential to improve the penetration ability through the depth of the tumor tissue to enhance drug intracellular delivery and antitumor bioactivity.

Stem Cell-Friendly Scaffold Biomaterials: Applications for Bone Tissue Engineering and Regenerative Medicine

Bone is a dynamic organ with high regenerative potential and provides essential biological functions in the body, such as providing body mobility and protection of internal organs, regulating hematopoietic cell homeostasis, and serving as important mineral reservoir. Bone defects, which can be caused by trauma, cancer and bone disorders, pose formidable public health burdens. Even though autologous bone grafts, allografts, or xenografts have been used clinically, repairing large bone defects remains as a significant clinical challenge. Bone tissue engineering (BTE) emerged as a promising solution to overcome the limitations of autografts and allografts. Ideal bone tissue engineering is to induce bone regeneration through the synergistic integration of biomaterial scaffolds, bone progenitor cells, and bone-forming factors. Successful stem cell-based BTE requires a combination of abundant mesenchymal progenitors with osteogenic potential, suitable biofactors to drive osteogenic differentiation, and cell-friendly scaffold biomaterials. Thus, the crux of BTE lies within the use of cell-friendly biomaterials as scaffolds to overcome extensive bone defects. In this review, we focus on the biocompatibility and cell-friendly features of commonly used scaffold materials, including inorganic compound-based ceramics, natural polymers, synthetic polymers, decellularized extracellular matrix, and in many cases, composite scaffolds using the above existing biomaterials. It is conceivable that combinations of bioactive materials, progenitor cells, growth factors, functionalization techniques, and biomimetic scaffold designs, along with 3D bioprinting technology, will unleash a new era of complex BTE scaffolds tailored to patient-specific applications.

Recent Advances in Marine-Based Nutraceuticals and Their Health Benefits

The oceans have been the Earth's most valuable source of food. They have now also become a valuable and versatile source of bioactive compounds. The significance of marine organisms as a natural source of new substances that may contribute to the food sector and the overall health of humans are expanding. This review is an update on the recent studies of functional seafood compounds (chitin and chitosan, pigments from algae, fish lipids and omega-3 fatty acids, essential amino acids and bioactive proteins/peptides, polysaccharides, phenolic compounds, and minerals) focusing on their potential use as nutraceuticals and health benefits.

Nanotechnological strategies for systemic microbial infections treatment: A review

Systemic infections is one of the major causes of mortality worldwide, and a shortage of drug approaches applied for the rapid and necessary treatment contribute to increase the levels of death in affected patients. Several drug delivery systems based in nanotechnology such as metallic nanoparticles, liposomes, nanoemulsion, microemulsion, polymeric nanoparticles, solid lipid nanoparticles, dendrimers, hydrogels and liquid crystals can contribute in the biological performance of active substances for the treatment of microbial diseases triggered by fungi, bacteria, virus and parasites. In the presentation of these statements, this review article present and demonstrate the effectiveness of these drug delivery systems for the treatment of systemic diseases caused by several microorganisms, through a review of studies on scientific literature worldwide that contributes to better information for the most diverse professionals from the areas of health sciences. The studies demonstrated that the drug delivery systems described can contribute to the therapeutic scenario of these diseases, being classified as safe, active platforms and with therapeutic versatility.

Hydroxyapatite Particles—Directing the Cellular Activity in Bone Regeneration Processes: An Up-To-Date Review

Tissue engineering has evolved quickly over the years and provided three generations of scaffolds for bone tissue applications. Numerous materials have been used to induce the desired effect at cellular levels. Mechano-transduction is a phenomenon which is now gaining the attention and focus of tissue engineering researchers. The idea of controlling the cellular fate and inducing a proper response of the human body in contact with different tissue-engineered systems is now under investigation. Moreover, in order to avoid the appearance of on-site infections and the need for a second surgery, scaffolds with dual functionality are now being developed. Hydroxyapatite (HA) is an intensively studied material in this field and various combinations are under examination for the development of such scaffolds. Various techniques were exploited over the years for HA scaffold production, in order to obtain the most accurate matrix which can mimic the native bone tissue and restore its function. Biomimetic scaffolds aim to direct the cellular fate by imitating the natural structure of the bone tissue in terms of porosity, topography, composition, and surface properties. HA particles are exploited in bone tissue engineering in many forms, such as pure or composite scaffolds or reinforcement agents. In this regard, the aim of this review is to offer a current state of art about the use and synthesis of hydroxyapatite particles and their interaction with the physiological media under certain circumstances.