Antibacterial properties of a bacterial cellulose CQD-TiO2 nanocomposite

Exploring the antimicrobial and antioxidant potential of bacterial cellulose-cerium oxide nanoparticles hydrogel: Design, characterization and biomedical properties

Bacterial cellulose (BC) is a promising natural polymer prized for its biocompatibility, microporosity, transparency, conformability, elasticity, and ability to maintain a moist wound environment while absorbing exudates. These attributes make BC an attractive material in biomedical applications, particularly in skin tissue repair. However, its lack of inherent antimicrobial activity limits its effectiveness. In this study, BC was enhanced by incorporating cerium (IV)-oxide (CeO2) nanoparticles, resulting in a series of bacterial cellulose-CeO2 (BC-CeO2) composite materials. Characterization via FESEM, XRD, and FTIR confirmed the successful synthesis of the composites. Notably, BC-CeO2-1 exhibited no cytotoxic or genotoxic effects on peripheral blood lymphocytes, and it additionally protected cells from genotoxic and cytotoxic effects in H2O2-treated cultures. Redox parameters in blood plasma samples displayed concentration and time-dependent trends in PAB and LPP assays. The incorporation of CeO2 nanoparticles also bolstered antimicrobial activity, expanding the potential biomedical applications of these composites.

Synthesis and drug release kinetics of ciprofloxacin from polyacrylamide/dextran/carbon quantum dots (PAM/Dex/CQD) hydrogels

Sustainable release of drug by utilizing β-cyclodextrin (β-CD) based inclusion complex (IC) is the prime objective of the present work. Herein, polyacrylamide/dextran containing carbon quantum dots (PAM/Dex/CQD) nanocomposite hydrogels are prepared by in situ polymerization of acrylamide. The incorporation of CQD triggers the change in orientation of the PAM/Dex polymeric chains to result the formation of stacked surface morphology of the hydrogel. The average particle size of CQD is found to be 4.13 nm from HRTEM analysis. As-synthesized nanocomposite hydrogel exhibits an optimum swelling ratio of 863 % in aqueous medium. The cytotoxicity study is conducted on HeLa cells by taking up to 2 μM concentration of the prepared nanocomposite hydrogel demonstrate 78 % cell viability. In present study, ciprofloxacin (Cipro) is taken as model drug that achieves release of 64.15 % in 32 h from β-Cipro@PAM/Dex/CQD hydrogels in acidic medium. From theoretical study, release rate constants, R2, Akaike information criterion (AIC) and model selection criterion (MSC) are computed to determine the best fitted kinetics model. Peppas-Sahlin model is the best fitted kinetics model for β-Cipro@PAM/Dex/CQD and concluded that the release of Cipro follows Fickian drug diffusion mechanism in acidic medium.

Catalytic and biomedical applications of nanocelluloses: A review of recent developments

Nanocelluloses exhibit immense potential in catalytic and biomedical applications. Their unique properties, biocompatibility, and versatility make them valuable in various industries, contributing to advancements in environmental sustainability, catalysis, energy conversion, drug delivery, tissue engineering, biosensing/imaging, and wound healing/dressings. Nanocellulose-based catalysts can efficiently remove pollutants from contaminated environments, contributing to sustainable and cleaner ecosystems. These materials can also be utilized as drug carriers, enabling targeted and controlled drug release. Their high surface area allows for efficient loading of therapeutic agents, while their biodegradability ensures safer and gradual release within the body. These targeted drug delivery systems enhance the efficacy of treatments and minimizes side effects. Moreover, nanocelluloses can serve as scaffolds in tissue engineering due to their structural integrity and biocompatibility. They provide a three-dimensional framework for cell growth and tissue regeneration, promoting the development of functional and biologically relevant tissues. Nanocellulose-based dressings have shown great promise in wound healing and dressings. Their ability to absorb exudates, maintain a moist environment, and promote cell proliferation and migration accelerates the wound healing process. Herein, the recent advancements pertaining to the catalytic and biomedical applications of nanocelluloses and their composites are deliberated, focusing on important challenges, advantages, limitations, and future prospects.

Antimicrobial and hydrophobic cellulose paper prepared by covalently attaching cinnamaldehyde for strawberries preservation

The demand for paper-based packaging materials as an alternative to incumbent disposable petroleum-derived polymers for food packaging applications is ever-growing. However, typical paper-based formats are not suitable for use in unconventional applications due to inherent limitations (e.g., excessive hydrophilicity, lack antimicrobial ability), and accordingly, enabling new capabilities is necessity. Herein, a simple and environmentally friendly strategy was proposed to introduce antimicrobial and hydrophobic functions to cellulose paper through successive chemical grafting of 3-aminopropyltriethoxysilane (APS) and cinnamaldehyde (CA). The results revealed that cellulose paper not only showed long-term antibacterial effect on different bacteria, but also inhibited a wide range of fungi. Encouragingly, the modified paper, which is fluorine-free, displays a high contact angle of 119.7°. Thus, even in the wet state, the modified paper can still maintain good mechanical strength. Meanwhile, the multifunctional composite papers have excellent biocompatibility and biodegradability. Compared with ordinary cellulose paper, multifunctional composite paper can effectively prolong the shelf life of strawberries. Therefore, the multifunctional composite paper represents good application potential as a fruit packaging material.

Nanocellulose-based platforms as a multipurpose carrier for drug and bioactive compounds: From active packaging to transdermal and anticancer applications

The nanocellulose has unique characteristics, such as biocompatibility, good mechanical strength, and low cytotoxicity. The nanocellulose crystalline portion is responsible for good mechanical resistance, while the amorphous portion is responsible for flexibility. Such features make it a promising candidate for multiple applications related to the modulation of substance release: targeted cancer therapy, transdermal drug delivery, and controlled-release packaging materials. Thus, in this study, we discussed nanocellulose as a multipurpose material for drug delivery and bioactive compound carriers in controlled delivery systems with varied applications in pharmaceutic fields. Herein, we focus on understanding key factors such as i) polymer-drug interactions and surface modification strategies in controlled release rates, ii) therapeutic efficacy, and iii) biocompatibility aspects. The tunable chemistry surface plays a fundamental approach limiting the quick release of active substances in drug delivery systems. Several works on a pre-clinical stage of investigation were overviewed, reporting robust evidence on nanocellulose to design bioactive compounds/drug delivery carriers based on stimuli-responsive drug release and controlled delivery systems for higher efficiency in cancer therapies, purposing target therapy and reduced side effects. Nanocellulose was also identified as a solid candidate material in active packaging for pharmaceutical products. Cellulose nanocrystals and bacterial cellulose demonstrated strong potential to overcome the challenge of controlled release profile and open novel insights in advanced active packaging materials for pharmaceutics with controlled release of antioxidant and antimicrobial substances. Moreover, the concept overview in this work might be extended in active food packaging technologies to flavor-releasing/absorbing systems or antimicrobial/antioxidant carriers for extending the shelf life of foods.

Effects of Synthesis Parameters on Structure and Antimicrobial Properties of Bacterial Cellulose/Hydroxyapatite/TiO2 Polymer-Ceramic Composite Material

Bacterial cellulose (BC) is a highly pure polysaccharide biopolymer that can be produced by various bacterial genera. Even though BC lacks functional properties, its porosity, three-dimensional network, and high specific surface area make it a suitable carrier for functional composite materials. In the present study, BC-producing bacteria were isolated from kombucha beverage and identified using a molecular method. Two sets of the BC hydrogels were produced in static conditions after four and seven days. Afterwards, two different synthesis pathways were applied for BC functionalization. The first method implied the incorporation of previously synthesized HAp/TiO2 nanocomposite using an immersion technique, while the second method included the functionalization of BC during the synthesis of HAp/TiO2 nanocomposite in the reaction mixture. The primary goal was to find the best method to obtain the functionalized material. Physicochemical and microstructural properties were analyzed by SEM, EDS, FTIR, and XRD methods. Further properties were examined by tensile test and thermogravimetric analysis, and antimicrobial activity was assessed by a total plate count assay. The results showed that HAp/TiO2 was successfully incorporated into the produced BC hydrogels using both methods. The applied methods of incorporation influenced the differences in morphology, phase distribution, mechanical and thermal properties, and antimicrobial activity against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 12453), and Candida albicans (ATCC 10231). Composite material can be recommended for further development and application in environments that are suitable for diseases spreading.

The effect of TiO2 nanoparticles on bacterial growth: the effect of particle size and their structure - a systematic review

One of the widely used microbiological methods to determine the toxicity of chemicals, catalysts, and other types of materials is the minimum inhibitory concentration (MIC) test. The present study aims to investigate the influence of composition of composite materials based on TiO2 and their particle size as well as bacterial type and shape based on the MIC values reported in the literature. The results show that among the 36 articles selected, most of the studies used Escherichia coli (E. coli) (26) and Staphylococcus aureus (S. aureus) (19) bacteria to determine MIC values. This study revealed that the MIC in values below 70 µg ml-1 for S. aureus was lower than that for E. coli bacteria (below 200 µg ml-1). Importantly, MIC value decreased from 60.6 to 7.66 µg ml-1 with decrease in the size of nanoparticles. It follows from the increased surface area for smaller-sized particles, thus increased interaction with bacteria during MIC test.

A review of carbon nanomaterials/bacterial cellulose composites for nanomedicine applications

Carbon nanomaterials (CNMs) mainly include fullerene, carbon nanotubes, graphene, carbon quantum dots, nanodiamonds, and their derivatives. As a new type of material in the field of nanomaterials, it has outstanding physical and chemical properties, such as minor size effects, substantial specific surface area, extremely high reaction activity, biocompatibility, and chemical stability, which have attracted widespread attention in the medical community in the past decade. However, the single use of carbon nanomaterials has problems such as self-aggregation and poor water solubility. Researchers have recently combined them with bacterial cellulose to form a new intelligent composite material to improve the defects of carbon nanomaterials. This composite material has been widely synthesized and used in targeted drug delivery, biosensors, antibacterial dressings, tissue engineering scaffolds, and other nanomedicine fields. This paper mainly reviews the research progress of carbon nanomaterials based on bacterial cellulose in nanomedicine. In addition, the potential cytotoxicity of these composite materials and their components in vitro and in vivo was discussed, as well as the challenges and gaps that need to be addressed in future clinical applications.

Bacterial cellulose impregnated with andaliman (Zanthoxylum acanthopodium) microencapsulation as diabetic wound dressing

Diabetic foot ulcer (DFU) is a common complication of diabetes mellitus which can cause infection, amputation and even death. One of many treatments that can be applied to support the DFU healing processes is by using wound dressings. Bacterial cellulose (BC) is a good material to be used as a wound dressing. However, some of the limitations of BC to be applied as wound dressing are does not possess antibacterial properties and support the healing process. Andaliman (Zanthoxylum acanthopodium) is known to have antioxidant, antibacterial and anti-inflammatory abilities that can support BC as a wound dressing. This research focused on the manufacture of BC/Z. acanthopodium microencapsulated wound dressing composites and evaluate their potential as a DFU wound dressing with a variety of gelatin composition in microencapsulation. The results of FTIR and SEM analysis showed that the Z. acanthopodium impregnation process in BC was successful. The variation of gelatine that used in microencapsulation affected the morphological and effectiveness of the wound dressing. However, overall, the wound dressings showed good antibacterial effect on E. coli and S. aureus bacteria and accelerating the wound closure process 8 times faster (BCAMc12) on the 17th day compared to wounds that did not receive any treatment.

Exploring the bioactivity of reduced graphene oxide and TiO2 nanocomposite for the regenerative medicinal applications

Millions of people globally suffer from issues related to chronic wounds due to infection, burn, obesity, and diabetes. Nanocomposite with antibacterial and anti-inflammatory properties is a promising material to promote wound healing. This investigation primarily aims to synthesize reduced graphene oxide and titanium dioxide (rGO@TiO2) nanocomposite for wound healing applications. The rGO@TiO2 nanocomposite was synthesized by the one-step hydrothermal technique, and the physicochemical characterization of synthesized nanocomposite was performed by X-ray diffraction, Fourier transforms infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, and dynamic light scattering. Further, the nanocomposite antibacterial, cytotoxicity, and wound-healing properties were analyzed by disc diffusion method, MTT assay, and in vitro scratch assay, respectively. Based on the TEM images, the average particle size of TiO2 nanoparticles was around 9.26 ± 1.83 nm. The characteristics peak of Ti-O-Ti bonds was observed between 500 and 850 cm-1 in the Fourier transforms infrared spectrum. The Raman spectrum of graphene oxide (GO) was obtained for bands D and G at 1354 cm-1 and at 1593 cm-1, respectively. This GO peak intensity was reduced in rGO, revealing the oxygen functional group reduction. Moreover, the rGO@TiO2 nanocomposite exhibited dose-dependent antibacterial properties against the positive and negative bacterium. The cytotoxicity for 5-100 µg/mL of rGO@TiO2 nanocomposite was above the half-maximal inhibitory concentration value. The in vitro scratch assay for rGO@TiO2 indicates that the nanocomposite promotes cell proliferation and migration. The nanocomposite recovered the wound within 48 h. The rGO@TiO2 nanocomposite shows potential materials for wound healing applications.

Symbiotic Antimicrobial Effects of Cellulose-Based Bio-Nanocomposite for Disease Management of Agricultural Crops

In the present work, a bionanocomposite for plant crop protection was prepared by non-toxic biocompatible & biodegradable nanomaterials (Cellulose & TiO2 ) to utilize its synergistic effects against antimicrobial pathogens. The commercially available microcrystalline cellulose has been reduced to a nanometric scale regime using acid hydrolysis, while the standard TiO2 nano-powder of particle size ~20 nm has been used to prepare their nanocomposite (NC). The antibacterial studies via agar well diffusion method demonstrated that after 72 h of incubation, parent nanomaterials Ncell and TiO2 were not showing any activity against phytopathogens X. campestris pv. campestris, and Clavibacter while the nanocomposite's NC's were still effective depicting both bacteriostatic and bactericidal actions. However, the bacterial growth of biocontrol P. fluorescence was not affected by Ncell, TiO2 NPs and NC after 72 h of incubation. The antifungal testing results via poison food agar assay method suggest that the nanocomposite, along with Ncell and TiO2 NPs, exhibited strong inhibition of fungal growth of Phytophthora Spp at 0.125 mg/ml concentration while for F. graminearum, similar effect was observed at 0.25 mg/ml concentration. The nanocomposite has proved its potential by exhibiting longer & stronger synergistic effects against plant pathogens as a good antimicrobial agent for protection of agricultural crops.

Preparation and characterization of pH-sensitive chitosan/starch/MoS2 nanocomposite for control release of curcumin macromolecules drug delivery; application in the breast cancer treatment

In this work, chitosan (CS), Starch (S), and Molybdenum Disulfide (MoS2) were combined to create a nanocarrier that was utilized to treat breast cancer using the MCF-7 cell line. To analyze the features of the nanocarrier, Fourier-transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD) tests were performed, respectively, to discover physical interactions and chemical bonding. Field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), and zeta potential analyses were performed and reported to determine the structural characteristics and morphology of nanoparticles, size distribution, and surface charge of nanocarriers, respectively. The average size of the nanocomposite was measured at around 279 nm, and the surface charge of the nanocarrier was determined to be +86.31 mV. The entrapment and drug loading efficiency of nanocarriers were 87.25 % and 46.5 %, respectively, which is an acceptable value. The kinetics and release mode of the drug were investigated, and it was found that the synthesized nanocarrier was sensitive to pH and that its release was stable. The amount of the nanocarriers' toxicity and cell death were evaluated using MTT tests and flow cytometry, respectively. In the present study, the nanocarrier was wholly nontoxic and had anticancer properties against the MCF-7 cell line. This nanocarrier is very important due to its non-toxicity and sensitivity to pH and can be used in drug delivery and medical applications.

Nano Ag/PPy Biocomposites Based on Graphene Oxide Modified Bacterial Cellulose from the Juice of Xinhui Citrus and Its Antibacterial Activity

Bacterial cellulose (BC) is a green, natural biopolymer with excellent biocompatibility and a film-forming ability. However, its lack of inherent antibacterial activity restricts its application in medical materials and food preservation. In this study, BC derived from the juice of discarded Xinhui citrus was obtained through fermentation and further modified in situ with graphene oxide (GO) to obtain BC(GO). Subsequently, BC(GO) was loaded with cell-compatible polypyrrole (PPy) and antibacterial agent silver nanoparticles (AgNPs) to prepare Ag-PPy/BC(GO) composite films. Composite films were characterized using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) to evaluate their chemical structure and morphology. The results demonstrate effective adsorption of PPy and AgNPs onto the surface of BC nanofibers modified with GO. Antibacterial experiments reveal synergistic antibacterial effects of PPy and AgNPs. The Ag-PPy/BC(GO) membranes exhibit strong antibacterial activity against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with 48-h growth inhibition rates of 75-84% and 82-84%, respectively.

Targeted Anticancer Drug Delivery Using Chitosan, Carbon Quantum Dots, and Aptamers to Deliver Ganoderic Acid and 5-Fluorouracil

Breast cancer is a malignancy that affects mostly females and is among the most lethal types of cancer. The ligand-functionalized nanoparticles used in the nano-drug delivery system offer enormous potential for cancer treatments. This work devised a promising approach to increase drug loading efficacy and produce sustained release of 5-fluorouracil (5-FU) and Ganoderic acid (GA) as model drugs for breast cancer. Chitosan, aptamer, and carbon quantum dot (CS/Apt/COQ) hydrogels were initially synthesized as a pH-sensitive and biocompatible delivery system. Then, CS/Apt/COQ NPs loaded with 5-FU-GA were made using the W/O/W emulsification method. FT-IR, XRD, DLS, zeta potentiometer, and SEM were used to analyze NP's chemical structure, particle size, and shape. Cell viability was measured using MTT assays in vitro using the MCF-7 cell lines. Real-time PCR measured cell apoptotic gene expression. XRD and FT-IR investigations validated nanocarrier production and revealed their crystalline structure and molecular interactions. DLS showed that nanocarriers include NPs with an average size of 250.6 nm and PDI of 0.057. SEM showed their spherical form, and zeta potential studies showed an average surface charge of +37.8 mV. pH 5.4 had a highly effective and prolonged drug release profile, releasing virtually all 5-FU and GA in 48 h. Entrapment efficiency percentages for 5-FU and GA were 84.7±5.2 and 80.2 %±2.3, respectively. The 5-FU-GA-CS-CQD-Apt group induced the highest cell death, with just 57.9 % of the MCF-7 cells surviving following treatment. 5-FU and GA in CS-CQD-Apt enhanced apoptotic induction by flow cytometry. 5-FU-GA-CS-CQD-Apt also elevated Caspase 9 and downregulated Bcl2. Accordingly, the produced NPs may serve as pH-sensitive nano vehicles for the controlled release of 5-FU and GA in treating breast cancer.

Synthesis and characterization of biological macromolecules double emulsion based on carboxymethylcellulose/gelatin hydrogel incorporated with ZIF-8 as metal organic frameworks for sustained anti-cancer drug release

The field of nanotechnology has introduced novel prospects for drug delivery systems, which have the potential to supplant conventional chemotherapy with reduced adverse effects. Despite being a promising porous material, ZIF-8, a metal-organic framework, tends to agglomerate in water, which limits its applicability. In order to resolve this problem, we added ZIF-8 to hydrogels consisting of gelatin and carboxymethylcellulose. This improved their mechanical strength and stability while avoiding aggregation. We utilized double emulsions with the hydrogels' biological macromolecules to construct drug carriers with enhanced control over drug release. The nanocarriers were subjected to various analytical techniques for characterization, such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), zeta potential, and dynamic light scattering (DLS). The findings of our study revealed that the mean size of the produced nanocarriers were 250 nm, and their zeta potential was -40.1 mV, which suggests favorable stability. The synthesized nanocarriers were found to exhibit cytotoxicity towards cancer cells, as evidenced by the results of MTT assays and flow cytometry tests. The cell viability percentage was determined to be 55 % for the prepared nanomedicine versus 70 % for the free drug. In summary, our study illustrates that the integration of ZIF-8 into hydrogels produces drug delivery systems with improved characteristics. Furthermore, the prepared nanocarriers exhibit potential for future investigation and advancement.

Nanocomposite of chitosan/gelatin/carbon quantum dots as a biocompatible and efficient nanocarrier for improving the Curcumin delivery restrictions to treat brain cancer

Curcumin (CUR) is among the most appropriate and natural-based anticancer drugs that can be applied effectively treat different classes of cancers. However, CUR suffers from a low half-life and stability in the body, which has restricted the efficacy of its delivery applications. This study is dedicated to introducing the pH-sensitive nanocomposite of chitosan (CS)/gelatin (GE)/carbon quantum dots (CQDs) as an applicable nanocarrier for enhancing CUR half-life and its delivery restrictions. The CS/GE hydrogel was synthesized by the physical crosslinking method, which improves the biocompatibility of this hydrogel. Moreover, the water-in-oil-in-water (W/O/W) double emulsion approach is involved in fabricating the drug-loaded CS/GE/CQDs@CUR nanocomposite. Afterward, drug encapsulation (EE) and loading efficiencies (LE) have been determined. Furthermore, FTIR and XRD assessments were performed to confirm the CUR incorporation into the prepared nanocarrier and crystalline features of the nanoparticles. Then, by employing Zeta potential and dynamic light scattering (DLS) analysis, the size distribution and stability of the drug-loaded nanocomposites have been assessed, which indicated monodisperse and stable nanoparticles. Furthermore, field emission scanning electron microscopy (FE-SEM) was utilized that confirmed the homogeneous distribution of the nanoparticles with smooth and quite spherical structures. In vitro drug release pattern was studied and the kinetic analysis was performed using a curve fitting technique to determine the governing release mechanism at both acidic pH and physiological conditions. The obtained outcomes from release data revealed a controlled release behavior with a 22-hour half-life, while the EE% and EL% were acquired at 46.75 % and 87.5 %, respectively. In addition, the MTT assay has been carried out on U-87 MG cell lines to evaluate the cytotoxicity of the nanocomposite. The findings showed that the fabricated nanocomposite of CS/GE/CQDs can be assumed as a biocompatible CUR nanocarrier, while the drug-loaded nanocomposite of CS/GE/CQDs@CUR showed enhanced cytotoxicity compared to the pure CUR. Based on the obtained results, this study suggests the CS/GE/CQDs nanocomposite as a biocompatible and potential nanocarrier for ameliorating CUR delivery restrictions to treat brain cancers.

Carboxymethyl cellulose/starch/reduced graphene oxide composite as a pH-sensitive nanocarrier for curcumin drug delivery

Nanocomposites are promising drug carriers to treat terminal cancers with few adverse effects. Herein, nanocomposite hydrogels composed of carboxymethyl cellulose (CMC)/starch/reduced graphene oxide (RGO) were synthesized via a green chemistry approach and then encapsulated in double nanoemulsions to act as pH-responsive delivery systems for curcumin, a potential antitumor drug. A water/oil/water nanoemulsion containing bitter almond oil served as a membrane surrounding the nanocarrier to control drug release. DLS and zeta potential measurements were used to estimate the size and confirm the stability of curcumin-loaded nanocarriers. The intermolecular interactions, crystalline structure and morphology of the nanocarriers were analyzed through FTIR spectroscopy, XRD and FESEM, respectively. The drug loading and entrapment efficiencies were significantly improved compared to previously reported curcumin delivery systems. In vitro release experiments demonstrated the pH-responsiveness of the nanocarriers and the faster curcumin release at a lower pH. The MTT assay revealed the increased toxicity of the nanocomposites against MCF-7 cancer cells compared to CMC, CMC/RGO or free curcumin. Apoptosis was detected in MCF-7 cells via flow cytometry tests. The results obtained herein support that the developed nanocarriers are stable, uniform and effective delivery systems for a sustained and pH-sensitive curcumin release.

Green synthesized polyvinylpyrrolidone/titanium dioxide hydrogel nanocomposite modified with agarose macromolecules for sustained and pH-responsive release of anticancer drug

Cancer, as one of the most challenging diseases of the last century, has a significant number of patients and deaths every year. Various strategies have been explored for the treatment of cancer. Chemotherapy is one of the methods of treating cancer. Doxorubicin is one of the compounds used in chemotherapy to kill cancer cells. Due to their unique properties and low toxicity, metal oxide nanoparticles are effective in combination therapy and increase the effectiveness of anti-cancer compounds. The limited in vivo circulatory period, poor solubility, and inadequate penetration of doxorubicin (DOX) restrict its use in cancer treatment, notwithstanding its attractive characteristics. It is possible to circumvent some of the difficulties in cancer therapy by using green synthesized pH-responsive nanocomposite consisting of polyvinylpyrrolidone (PVP), titanium dioxide (TiO₂) modified with agarose (Ag) macromolecules. TiO₂ incorporation into the PVP-Ag nanocomposite resulted in limited increased loading and encapsulation efficiencies from 41 % to 47 % and 84 % to 88.5 %, respectively. DOX diffusion among normal cells is prevented by the PVP-Ag-TiO₂ nanocarrier at pH = 7.4, though the acidic intracellular microenvironments activate the PVP-Ag-TiO₂ nanocarrier at pH = 5.4. Characterization of the nanocarrier was performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrophotometry, field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), and zeta potential. The average particle size and the zeta potential of the particles showed values of 349.8 nm and +57 mV, respectively. In vitro release after 96 h showed a release rate of 92 % at pH 7.4 and a release rate of 96 % at pH 5.4. Meanwhile, the initial release after 24 h was 42 % for pH 7.4 and 76 % for pH 5.4. As shown by an MTT analysis on MCF-7 cells, the toxicity of DOX-loaded PVP-Ag-TiO₂ nanocomposite was substantially greater than that of unbound DOX and PVP-Ag-TiO₂. After integrating TiO₂ nanomaterials into the PVP-Ag-DOX nanocarrier, flow cytometry data showed a greater stimulation of cell death. These data indicate that the DOX-loaded nanocomposite is a suitable alternative for drug delivery systems.

Optimization of electrospun CQDs-Fe3O4-RE loaded PVA-cellulose nanofibrils via central composite design for wound dressing applications: Kinetics and in vitro release study

Wound skin infections can cause significant morbidity and even mortality. Cellulose nanofibrils (CNFs) are a type of nano cellulose that have reached notable attention due to their inimitable properties. In this study, in order to prepare a novel wound dressing, CNFs are composited with poly (vinyl alcohol) (PVA) to enhance mechanical properties and increase cell proliferation and migration. Also, carbon quantum dots (CQDs)- Fe₃O₄ was introduced as a novel antibacterial, and rosemary extract (RE) was composited with this to reduce its cell toxicity. PVA - CNFs/ CQDs- Fe₃O₄- RE nanofiber was prepared using the electrospinning method. Then, to maximize tensile strength, total elongation, and percentage swelling of PVA - CNFs/ CQDs- Fe₃O₄- RE electrospun nanofiber, parameters of crosslinking duration and the concentration of CQDs- Fe₃O₄-RE were optimized employing central composite design, and optimized electrospun nanofiber (OEN) as a novel wound dressing was prepared. Results exhibited, the high antibacterial properties of CQDs-Fe₃O₄-RE. Also, CNFs and CQDs- Fe₃O₄-RE increased the tensile strength of OEN. Moreover, CNFs and RE reduce wound area percentages and increase the percentage of cell viability, respectively. Therefore, OEN was introduced as a suitable wound dressing due to its appropriate surface roughness, mechanical properties, WVTR, biodegradation, prolonged release, non-toxicity, and high cell proliferation and migration ability.

Cellulose Nanofiber-Coated Perfluoropentane Droplets: Fabrication and Biocompatibility Study

Purpose

To study the effect of cellulose nanofiber (CNF)-shelled perfluoropentane (PFP) droplets on the cell viability of 4T1 breast cancer cells with or without the addition of non-encapsulated paclitaxel.

Methods

The CNF-shelled PFP droplets were produced by mixing a CNF suspension and PFP using a homogenizer. The volume size distribution and concentration of CNF-shelled PFP droplets were estimated from images taken with an optical microscope and analyzed using Fiji software and an in-house Matlab script. The thermal stability was qualitatively assessed by comparing the size distribution and concentration of CNF-shelled PFP droplets at room temperature (~22°) and 37°C. The cell viability of 4T1 cells was measured using a 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, a hemolysis assay was performed to assess blood compatibility of CNF-shelled PFP droplets.

Results

The droplet diameter and concentration of CNF-shelled PFP droplets decreased after 48 hours at both room temperature and 37°C. In addition, the decrease in concentration was more significant at 37°C, from 3.50 ± 0.64×10⁶ droplets/mL to 1.94 ± 0.10×10⁶ droplets/mL, than at room temperature, from 3.65 ± 0.29×10⁶ droplets/mL to 2.56 ± 0.22×10⁶ droplets/mL. The 4T1 cell viability decreased with increased exposure time and concentration of paclitaxel, but it was not affected by the presence of CNF-shelled PFP droplets. No hemolysis was observed at any concentration of CNF-shelled PFP droplets.

Conclusion

CNF-shelled PFP droplets have the potential to be applied as drug carriers in ultrasound-mediated therapy.

PVA-Based Nanofibers Containing Chitosan Modified with Graphene Oxide and Carbon Quantum Dot-Doped TiO2 Enhance Wound Healing in a Rat Model

Electrospun nanofibrous constructs based on nanoparticles and biopolymers have recently been used in tissue engineering because of their similarity to the extracellular matrix in nature. In this study, electrospun chitosan-carbon quantum dot-titanium dioxide-graphene oxide (CS-CQD-TiO₂-GO) nanofibrous mats were synthesized for use as wound dressings by the electrospinning method. To increase the biodegradation rate and water resistance, the fabricated nanofibrous mats were cross-linked. SEM images showed a uniform and coherent structure of CS-CQD-TiO₂-GO nanocomposites and CS-CQD-TiO₂-GO electrospun nanofibers mats. FTIR analysis, XRD pattern, SEM mapping, and EDS spectrum demonstrate the accuracy of the synthesis as well as the elemental and chemical structure of the nanofibrous mat. The water contact angle indicated that the nanofibrous mat had a hydrophilic property, which is essential for controlling wound exudates. The tensile strength and elongation tests showed that the nanofibrous mat has suitable mechanical properties for wound dressing, including significant flexibility and strength. Interestingly, antimicrobial testing illustrated that the fabricated nanofibrous mat had antibacterial activity against Gram-negative and Gram-positive bacteria. Appropriate cell viability and cytocompatibility of treated mouse fibroblast NIH3T3 cells with the nanofibrous mat were determined using an MTT assay. The animal study results confirmed the proper potential of the nanofibrous mat in wound dressing applications.

A comprehensive review on the applications of carbon-based nanostructures in wound healing: from antibacterial aspects to cell growth stimulation

A wound is defined as damage to the integrity of biological tissue, including skin, mucous membranes, and organ tissues. The treatment of these injuries is an important challenge for medical researchers. Various materials have been used for wound healing and dressing applications among which carbon nanomaterials have attracted significant attention due to their remarkable properties. In the present review, the latest studies on the application of carbon nanomaterials including graphene oxide (GO), reduced graphene oxide (rGO), carbon dots (CDs), carbon quantum dots (CQDs), carbon nanotubes (CNTs), carbon nanofibers (CNFs), and nanodiamonds (NDs) in wound dressing applications are evaluated. Also, a variety of carbon-based nanocomposites with advantages such as biocompatibility, hemocompatibility, reduced wound healing time, antibacterial properties, cell-adhesion, enhanced mechanical properties, and enhanced permeability to oxygen has been reported for the treatment of various wounds.

Evolution of Bacterial Cellulose in Cosmetic Applications: An Updated Systematic Review

In recent decades, there has been an increase in environmental problems caused by cosmetic products derived from toxic substances. Based on this issue, researchers and developers of new beauty cosmetics are looking for new natural alternatives that work well for the consumer and have biodegradable characteristics. This systematic review highlights the major publications of bacterial cellulose used strictly for cosmetics in the last 10 years. Bacterial cellulose is a natural product with great cosmetic properties and low cost that has shown excellent results. This study aimed at collecting rigorous information on bacterial cellulose in the cosmetic field in the last decade to produce a systematized review. A comprehensive search was conducted with selected descriptors involving the topic of "bacterial cellulose", "cosmetics", "clean beauty", and "skin mask". Seventy studies were found, which went through exclusion criteria that selected only those related to the topic that was searched. In the 12 remaining studies that met the criteria, bacterial cellulose showed conditions for use as a mask-forming product for facial care. The increase in the number of publications concerning bacterial cellulose in cosmetics in the last ten years is a strong indicator that this is a growing area for both research and the industry.

Bioresource-Functionalized Quantum Dots for Energy Generation and Storage: Recent Advances and Feature Perspective

The exponential increase in global energy demand in daily life prompts us to search for a bioresource for energy production and storage. Therefore, in developing countries with large populations, there is a need for alternative energy resources to compensate for the energy deficit in an environmentally friendly way and to be independent in their energy demands. The objective of this review article is to compile and evaluate the progress in the development of quantum dots (QDs) for energy generation and storage. Therefore, this article discusses the energy scenario by presenting the basic concepts and advances of various solar cells, providing an overview of energy storage systems (supercapacitors and batteries), and highlighting the research progress to date and future opportunities. This exploratory study will examine the systematic and sequential advances in all three generations of solar cells, namely perovskite solar cells, dye-sensitized solar cells, Si cells, and thin-film solar cells. The discussion will focus on the development of novel QDs that are economical, efficient, and stable. In addition, the current status of high-performance devices for each technology will be discussed in detail. Finally, the prospects, opportunities for improvement, and future trends in the development of cost-effective and efficient QDs for solar cells and storage from biological resources will be highlighted.

Two-Dimensional Graphitic Carbon Nitride (g-C3N4) Nanosheets and Their Derivatives for Diagnosis and Detection Applications

The early diagnosis of certain fatal diseases is vital for preventing severe consequences and contributes to a more effective treatment. Despite numerous conventional methods to realize this goal, employing nanobiosensors is a novel approach that provides a fast and precise detection. Recently, nanomaterials have been widely applied as biosensors with distinctive features. Graphite phase carbon nitride (g-C₃N₄) is a two-dimensional (2D) carbon-based nanostructure that has received attention in biosensing. Biocompatibility, biodegradability, semiconductivity, high photoluminescence yield, low-cost synthesis, easy production process, antimicrobial activity, and high stability are prominent properties that have rendered g-C₃N₄ a promising candidate to be used in electrochemical, optical, and other kinds of biosensors. This review presents the g-C₃N₄ unique features, synthesis methods, and g-C₃N₄-based nanomaterials. In addition, recent relevant studies on using g-C₃N₄ in biosensors in regard to improving treatment pathways are reviewed.

Construction of Aptamer-Based Nanobiosensor for Breast Cancer Biomarkers Detection Utilizing g-C3N4/Magnetic Nano-Structure

An electrochemical aptasensor has been developed to determine breast cancer biomarkers (CA 15-3). Aptamer chains were immobilized on the surface of the electrode by g-C₃N₄/Fe₃O₄ nanoparticles, which increased the conductivity and active surface area of the electrode. X-ray diffraction analysis (XRD), Fourier-transformed infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) measurements have been carried out to characterize the nanomaterials. Cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy have been used to characterize the developed electrode. The results demonstrate that the modified electrode has better selectivity for CA 15-3 compared to other biological molecules. It has a good electrochemical response to CA 15-3 with a detection limit of 0.2 UmL^-1 and a linear response between 1 and 9 UmL^-1. It has been used as a label-free sensor in potassium ferrocyanide medium and as methylene blue-labeled in phosphate buffer medium. This electrode was successfully applied to analyze the serum of diseased and healthy individuals, which corroborates its high potential for biosensing applications, especially for the diagnosis of breast cancer.

Bioactive inorganic particles-based biomaterials for skin tissue engineering

The challenge for treatment of severe cutaneous wound poses an urgent clinical need for the development of biomaterials to promote skin regeneration. In the past few decades, introduction of inorganic components into material system has become a promising strategy for improving performances of biomaterials in the process of tissue repair. In this review, we provide a current overview of the development of bioactive inorganic particles-based biomaterials used for skin tissue engineering. We highlight the three stages in the evolution of the bioactive inorganic biomaterials applied to wound management, including single inorganic materials, inorganic/organic composite materials, and inorganic particles-based cell-encapsulated living systems. At every stage, the primary types of bioactive inorganic biomaterials are described, followed by citation of the related representative studies completed in recent years. Then we offer a brief exposition of typical approaches to construct the composite material systems with incorporation of inorganic components for wound healing. Finally, the conclusions and future directions are suggested for the development of novel bioactive inorganic particles-based biomaterials in the field of skin regeneration.

Effect of Bacterial Cellulose Plasma Treatment on the Biological Activity of Ag Nanoparticles Deposited Using Magnetron Deposition

New functional medical materials with antibacterial activity based on biocompatible bacterial cellulose (BC) and Ag nanoparticles (Ag NPs) were obtained. Bacterial cellulose films were prepared by stationary liquid-phase cultivation of the Gluconacetobacter hansenii strain GH-1/2008 in Hestrin-Schramm medium with glucose as a carbon source. To functionalize the surface and immobilize Ag NPs deposited by magnetron sputtering, BC films were treated with low-pressure oxygen-nitrogen plasma. The composition and structure of the nanomaterials were studied using transmission (TEM) and scanning (SEM) electron microscopy and X-ray photoelectron spectroscopy (XPS). Using electron microscopy, it was shown that on the surface of the fibrils that make up the network of bacterial cellulose, Ag particles are stabilized in the form of aggregates 5-35 nm in size. The XPS C 1s spectra show that after the deposition of Ag NPs, the relative intensities of the C-OH and O-C-O bonds are significantly reduced. This may indicate the destruction of BC oxypyran rings and the oxidation of alcohol groups. In the Ag 3d_5/2 spectrum, two states at 368.4 and 369.7 eV with relative intensities of 0.86 and 0.14 are distinguished, which are assigned to Ag⁰ state and Ag acetate, respectively. Nanocomposites based on plasma-treated BC and Ag nanoparticles deposited by magnetron sputtering (BCP-Ag) exhibited antimicrobial activity against Aspergillus niger, S. aureus and Bacillus subtilis.

Development of antibacterial and superabsorbent wound composite sponges containing carboxymethyl cellulose/gelatin/Cu-doped ZnO nanoparticles

This study aimed to develop a novel antibacterial and superabsorbent dressing by introducing the Cu-doped ZnO nanoparticles into the carboxymethyl cellulose/gelatin glutaraldehyde-crosslinked composite sponge that is fabricated by lyophilization method. Undoped and Cu-doped ZnO (Zn_1-xCu_xO, x = 0.03 and 0.05) nanoparticles were synthesized through the stabilizing agent-used precipitation process and characterized by XRD, FESEM, FTIR, and ICP-OES techniques. The XRD evaluation determined that the concentration of copper in ZnO is limited to below 5%. Additionally, The ICP-OES analysis confirmed the effect of the doping process on the ZnO crystalline structure by releasing more zinc and copper ions from Cu-doped ZnO, which resulted to improve antibacterial activity against Staphylococcus aureus and Escherichia coli bacterial strains. The effect of ZnO nanoparticles on the physical and mechanical performance of the optimized composite sponge indicated that the incorporation of 3 wt% ZnO nanoparticles produces a well-interconnected porous structure (~156 µm) with high water absorption (~3089%) and proper elongation (~49%) in a wet medium. The incorporation of Cu-doped ZnO nanoparticles enhanced antibacterial potential of the composite sponge. Meanwhile, all sponge groups are safe for viability, proliferation and adhesion of human dermal fibroblast cells. Overall, the obtained data has proved the potential of carboxymethyl cellulose/gelatin/Cu-doped ZnO dressing as a promising candidate for managing infected wounds.

Investigating the effect of nanoparticle on phenanthrene biodegradation by Labedella gwakjiensis strain KDI

Polycyclic aromatic hydrocarbons (PAHs), as persistent organic contaminants, are a major source of concern due to their toxic effect on ecosystems and human health. This study attempted to isolate halotolerant PAHs degrading bacteria from saline oil-contaminated soils. Among the isolates, strain KDI with the highest 16S rRNA gene sequence similarity to Labedella gwakjiensis was able to reduce surface tension (ST) from 65.42 to 26.60 mN m^-1 and increase the emulsification index to 81.04%, as a result of significant biosurfactant production. Response Surface Methodology (RSM) analysis was applied to optimize the factors, i.e. PAHs concentration and NaCl concentration as well as to determine the effect of these important variables on PAHs biodegradation. The Carbon Quantum Dots. Iron Oxide (CQDs.Fe₃O₄) nanoparticles were characterized by several popular analytical techniques, after which the effect of CQD.Fe₃O₄ nanoparticles on biodegradation was examined. PAHs biodegradation rate and efficiency of strain KDI to degrade PHE in the presence of CQD.Fe₃O₄ nanoparticles was analyzed by GC. According to the results during biodegradation both the concentration of PAHs and the amount of NaCl were effective. The biodegradation rate significantly increased in the presence of CQD.Fe₃O₄. The highest biodegradation of PHE occurred in the presence of 0.5 g/L of CQD.Fe₃O₄ which was 63.63% and 81.77% after 48 and 72 h of incubation. To the best of our knowledge, this is the first report on optimization of PAHs concentration and salinity by RSM and nanobioremediation of PHE using a bacterial strain in the presence of CQD.Fe₃O₄ nanoparticles.

Enhanced healing process of tooth sockets using strontium-doped TiO2

Prevention of residual ridge resorption is important for tooth socket healing in clinical treatment. As a well known biomaterial, titanium dioxide (TiO₂) has been reported to show desirable bone regeneration capability. On the other hand, strontium plays a role in maintaining normal function in organisms and balancing bone remodeling. Hence, we synthesized strontium-doped titanium dioxide mesoporous nanospheres functionalized with amino-group using diphenyl diisocyanate. After incorporation with segmented polyurethane, the obtained injectable SPU/Sr-TiO₂/MDI nanocomposite adhesive showed satisfactory antibacterial activity and cell nontoxicity. This nanocomposite was used for tooth socket healing, and greatly promoted the formation of new bone tissue in the tooth extraction socket.

Multi-Functional 3D-Printed Vat Photopolymerization Biomedical-Grade Resin Reinforced with Binary Nano Inclusions: The Effect of Cellulose Nanofibers and Antimicrobial Nanoparticle Agents

This study introduced binary nanoparticle (NP) inclusions into a biomedical-grade photosensitive resin (Biomed Clear-BC). Multi-functional, three-dimensional (3D) printed objects were manufactured via the vat photopolymerization additive manufacturing (AM) technique. Cellulose nanofibers (CNFs) as one dimensional (1D) nanomaterial have been utilized for the mechanical reinforcement of the resin, while three different spherical NPs, namely copper NPs (nCu), copper oxide NPs (nCuO), and a commercial antimicrobial powder (nAP), endowed the antimicrobial character. The nanoparticle loading was kept constant at 1.0 wt.% to elucidate any synergistic effects as a function of the filler loading. Raman, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) revealed the chemical/spectroscopic and thermal properties of the different manufactured samples. Scanning electron microscopy and Atomic Force Microscopy (AFM) revealed the morphology of the samples. Mechanical properties revealed the reinforcement mechanisms, namely that BC/CNF (1.0 wt.%) exhibited a 102% and 154% enhancement in strength and modulus, respectively, while BC/CNF(1.0 wt.%)/AP(1.0 wt.%) exhibited a 95% and 101% enhancement, as well as an antibacterial property, which was studied using a screening agar well diffusion method. This study opens the route towards novel, multi-functional materials for vat photopolymerization 3D printing biomedical applications, where mechanical reinforcement and antibacterial performance are typically required in the operational environment.

Properties and Applications of Graphene and Its Derivatives in Biosensors for Cancer Detection: A Comprehensive Review

Cancer is one of the deadliest diseases worldwide, and there is a critical need for diagnostic platforms for applications in early cancer detection. The diagnosis of cancer can be made by identifying abnormal cell characteristics such as functional changes, a number of vital proteins in the body, abnormal genetic mutations and structural changes, and so on. Identifying biomarker candidates such as DNA, RNA, mRNA, aptamers, metabolomic biomolecules, enzymes, and proteins is one of the most important challenges. In order to eliminate such challenges, emerging biomarkers can be identified by designing a suitable biosensor. One of the most powerful technologies in development is biosensor technology based on nanostructures. Recently, graphene and its derivatives have been used for diverse diagnostic and therapeutic approaches. Graphene-based biosensors have exhibited significant performance with excellent sensitivity, selectivity, stability, and a wide detection range. In this review, the principle of technology, advances, and challenges in graphene-based biosensors such as field-effect transistors (FET), fluorescence sensors, SPR biosensors, and electrochemical biosensors to detect different cancer cells is systematically discussed. Additionally, we provide an outlook on the properties, applications, and challenges of graphene and its derivatives, such as Graphene Oxide (GO), Reduced Graphene Oxide (RGO), and Graphene Quantum Dots (GQDs), in early cancer detection by nanobiosensors.

Bacterial cellulose as a potential biopolymer in biomedical applications: a state-of-the-art review

Throughout history, natural biomaterials have benefited society. Nevertheless, in recent years, tailoring natural materials for diverse biomedical applications accompanied with sustainability has become the focus. With the progress in the field of materials science, novel approaches for the production, processing, and functionalization of biomaterials to obtain specific architectures have become achievable. This review highlights an immensely adaptable natural biomaterial, bacterial cellulose (BC). BC is an emerging sustainable biopolymer with immense potential in the biomedical field due to its unique physical properties such as flexibility, high porosity, good water holding capacity, and small size; chemical properties such as high crystallinity, foldability, high purity, high polymerization degree, and easy modification; and biological characteristics such as biodegradability, biocompatibility, excellent biological affinity, and non-biotoxicity. The structure of BC consists of glucose monomer units polymerized via cellulose synthase in β-1-4 glucan chains, creating BC nano fibrillar bundles with a uniaxial orientation. BC-based composites have been extensively investigated for diverse biomedical applications due to their similarity to the extracellular matrix structure. The recent progress in nanotechnology allows the further modification of BC, producing novel BC-based biomaterials for various applications. In this review, we strengthen the existing knowledge on the production of BC and BC composites and their unique properties, and highlight the most recent advances, focusing mainly on the delivery of active pharmaceutical compounds, tissue engineering, and wound healing. Further, we endeavor to present the challenges and prospects for BC-associated composites for their application in the biomedical field.

Antibacterial, antifungal, antiviral, and photocatalytic activities of TiO2 nanoparticles, nanocomposites, and bio-nanocomposites: Recent advances and challenges

The applications of nanomaterials specifically metal and metal nanoparticles in various medical and industrial fields have been due to their unique properties compared to bulk materials. A combination of pharmacology and nanotechnology has helped the production of novel antimicrobial agents to control resistant microorganisms of bacteria and fungi. The properties of metal nanoparticles and metal oxides such as titanium dioxide (TiO2), zinc oxide (ZnO), silver (Ag), and copper (Cu) are well known as efficient antimicrobial agents. In particular, TiO2 nanoparticles have been considered as an attractive antimicrobial compound due to their photocatalytic intrinsic and their stable, non-toxic, inexpensive, and safe physicochemical properties. Therefore, in this review, recent advances and challenges of antibacterial, antifungal, antiviral, and photocatalytic activities of TiO2 nanoparticles, nanocomposites, and bio-nanocomposites are presented to help future studies.

The construct of triple responsive nanocomposite and its antibacterial effect

The current serious mismatch between the increasing severity of bacterial infections and antibiotic production capacity urgently requires the emergence of novel antimicrobial materials. In this paper, dopamine methacrylamide (DMA) and N-isopropylacrylamide (NIPAM) were polymerized as the monomers into a block copolymer poly(dopamine methacrylamide-block-N-isopropylacrylamide) (P(DA-NIP)) and then encapsulated with polydopamine-coated magnetic nanoparticle clusters (MNC) to produce an antibacterial nanocomposite (MNC@P(DA-NIP)). This nanocomposite has triple responses respectively to light, heat and magnetism, which endow MNC@P(DA-NIP) with the abilities to kill bacteria effectively and capture/release bacteria conveniently. Under near-infrared (NIR) light irradiation, MNC@P(DA-NIP) could significantly elevate the temperature through photothermal conversion. The increased temperature favored both the capture of bacteria on MNC@P(DA-NIP), and the damage of bacterial cells, causing bacterial death almost completely. While low temperatures could promote the release of dead bacteria from the nanocomposites, might through the recovery of the hydrophilic state of the outlayer PNIPAM. Moreover, thanks to the magnetic responsibility, MNC@P(DA-NIP) could be easily separated from the bacterial cells and perform better biofilm penetration. The results showed that the antibacterial effect of MNC@P(DA-NIP) was 3.5 times higher than that of MNC, and the recycling capacity of MNC@P(DA-NIP) was better than MNC@PDA. What's more, MNC@P(DA-NIP) possessed the excellent anti-biofilm properties under magnetic field (MF) and NIR. The most important features of the triple-responsive nanocomposites are excellent antibacterial effect, good recyclability and easy preparation, which provide the nanocomposites with great potential in eliminating harmful bacterial cells.

Improved photocatalytic activity of TiO2 nanoparticles through nitrogen and phosphorus co-doped carbon quantum dots: An experimental and theoretical study

In this work, we are developing a photocatalyst wherein, nitrogen and phosphorus co-doped carbon quantum dots are scaffolded on to TiO2 nanoparticles (NPCQDs/TiO2), denoted NPCT hereafter. The NPCT photocatalyst developed...

Membrane Technological Pathways and Inherent Structure of Bacterial Cellulose Composites for Drug Delivery

This report summarizes efforts undertaken in the area of drug delivery, with a look at further efforts made in the area of bacterial cellulose (BC) biomedical applications in general. There are many current methodologies (past and present) for the creation of BC membrane composites custom-engineered with drug delivery functionality, with brief consideration for very close applications within the broader category of biomedicine. The most emphasis was placed on the crucial aspects that open the door to the possibility of drug delivery or the potential for use as drug carriers. Additionally, consideration has been given to laboratory explorations as well as already established BC-drug delivery systems (DDS) that are either on the market commercially or have been patented in anticipation of future commercialization. The cellulose producing strains, current synthesis and growth pathways, critical aspects and intrinsic morphological features of BC were given maximum consideration, among other crucial aspects of BC DDS.

Modified Alginate Beads with Ethanol Extraction of Cratoxylum formosum and Polygonum odoratum for Antibacterial Activities

Bacteria contaminations in water are concerned as environmental effects including human health, so water treatment is required before use. Although using extracted plant is interesting because of their good chemical compounds for bacterial inhibitions, no study has applied the extracted plant in bead materials for disinfection in wastewater. The current research attempted to extract Cratoxylum formosum and Polygonum odoratum for the synthesis of C. formosum beads (CFB) and P. odoratum beads (POB), and their antibacterial efficiencies were investigated by agar diffusion tests, antibacterial batch tests, adsorption isotherm and kinetics, and material reusability. C. formosum and P. odoratum leaves were ethanol-extracted, and their bead materials (CFB and POB) were synthesized. Furthermore, their characterizations of surface area, chemical compositions, and chemical functional groups were investigated. For field emission scanning electron microscopy and focused ion beam (FESEM-FIB) analysis, CFB and POB had spherical shapes with coarse surfaces. Energy-dispersive X-ray spectrometry (EDX) analysis of CFB and POB illustrated five main chemical compositions, which were carbon (C), oxygen (O), calcium (Ca), chlorine (Cl), and sodium (Na), whereas Fourier transform infrared (FTIR) spectroscopy analysis identified seven main chemical functional groups, which were O-H, C-H, C=O, C=C, N-H, C-O, and C-Cl. Agar diffusion tests confirmed the abilities of CFB and POB to inhibit both Staphylococcus aureus and Escherichia coli, and batch experiments examined high antibacterial efficiencies of CFB of almost 100% on both bacterial types. The adsorption isotherm of CFB corresponded to the Freundlich model, which is related to the physiochemical adsorption process with multilayer or heterogeneous adsorption, and the adsorption kinetics of CFB was correlated to the pseudo-second-order kinetic model, which involved chemisorption relating to physiochemical interaction. Moreover, the desorption experiment confirmed the reusability of CFB. Therefore, CFB is a potential material to possibly apply for disinfection of wastewater.

Ultra pH-sensitive detection of total and free prostate-specific antigen using electrochemical aptasensor based on reduced graphene oxide/gold nanoparticles emphasis on TiO2/carbon quantum dots as a redox probe

The development of a rapid, sensitive, and straightforward detection method of prostate-specific antigen (PSA) is indispensable for the early diagnosis of prostate cancer (PCa). This work relates an electrochemical method using functionalized single-stranded DNA aptamer to diagnose PCa and benign prostate hyperplasia. The sensing platform relies on PSA recognition by aptamer/Au/GO-nanohybrid-modified glassy carbon electrode. Besides ferrocyanide TiO2/carbon quantum dots (CQDs) probe is used to investigate the effect of nanoparticle-containing electrolyte. Optimization of incubation time of aptamer/Au/GO-nanohybrid and volume fraction of nafion were done using Design Expert 10 software reporting 42.4 h and 0.095% V/V, respectively. In ferrocyanide medium, PSA detection as low as 3, 2.96, and 0.85 ng mL-1 was achieved with a dynamic range from 0.5 to 7 ng ml-1, in accord with clinical values, using cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy, respectively. Moreover, this sensor exhibited conspicuous performance in TiO2/CQDs-containing medium with different pH values of 5.4 and 8 to distinguish total PSA and free PSA, resulting in very low limit of detections, 0.028, and 0.007 ng ml-1, respectively. The results manifested the proposed system as a forthcoming sensor in a clinical and point of care analysis of PSA.