Morphological, Release and Antibacterial Performances of Amoxicillin-Loaded Cellulose Aerogels

Advancements in Aerogel Technology for Antimicrobial Therapy: A Review

This paper explores the latest advancements in aerogel technology for antimicrobial therapy, revealing their interesting capacity that could improve the current medical approaches for antimicrobial treatments. Aerogels are attractive matrices because they can have an antimicrobial effect on their own, but they can also provide efficient delivery of antimicrobial compounds. Their interesting properties, such as high porosity, ultra-lightweight, and large surface area, make them suitable for such applications. The fundamentals of aerogels and mechanisms of action are discussed. The paper also highlights aerogels' importance in addressing current pressing challenges related to infection management, like the limited drug delivery alternatives and growing resistance to antimicrobial agents. It also covers the potential applications of aerogels in antimicrobial therapy and their possible limitations.

Hybrid and Single-Component Flexible Aerogels for Biomedical Applications: A Review

The inherent disadvantages of traditional non-flexible aerogels, such as high fragility and moisture sensitivity, severely restrict their applications. To address these issues and make the aerogels efficient, especially for advanced medical applications, different techniques have been used to incorporate flexibility in aerogel materials. In recent years, a great boom in flexible aerogels has been observed, which has enabled them to be used in high-tech biomedical applications. The current study comprises a comprehensive review of the preparation techniques of pure polymeric-based hybrid and single-component aerogels and their use in biomedical applications. The biomedical applications of these hybrid aerogels will also be reviewed and discussed, where the flexible polymeric components in the aerogels provide the main contribution. The combination of highly controlled porosity, large internal surfaces, flexibility, and the ability to conform into 3D interconnected structures support versatile properties, which are required for numerous potential medical applications such as tissue engineering; drug delivery reservoir systems; biomedical implants like heart stents, pacemakers, and artificial heart valves; disease diagnosis; and the development of antibacterial materials. The present review also explores the different mechanical, chemical, and physical properties in numerical values, which are most wanted for the fabrication of different materials used in the biomedical fields.

Furanone loaded aerogels are effective antibiofilm therapeutics in a model of chronic Pseudomonas aeruginosa wound infection

Almost 80% of chronic wounds have a bacterial biofilm present. These wound biofilms are caused by a range of organisms and are often polymicrobial. Pseudomonas aeruginosa is one of the most common causative organisms in wound infections and readily forms biofilms in wounds. To coordinate this, P. aeruginosa uses a process known as quorum sensing. Structural homologues of the quorum sensing signalling molecules have been used to disrupt this communication and prevent biofilm formation by Pseudomonas. However, these compounds have not yet reached clinical use. Here, we report the production and characterisation of a lyophilised PVA aerogel for use in delivering furanones to wound biofilms. PVA aerogels successfully release a model antimicrobial and two naturally occurring furanones in an aqueous environment. Furanone loaded aerogels inhibited biofilm formation in P. aeruginosa by up to 98.80%. Further, furanone loaded aerogels successfully reduced total biomass of preformed biofilms. Treatment with a sotolon loaded aerogel yielded a 5.16 log reduction in viable biofilm bound cells in a novel model of chronic wound biofilm, equivalent to the current wound therapy Aquacel AG. These results highlight the potential utility of aerogels in drug delivery to infected wounds and supports the use of biofilm inhibitory compounds as wound therapeutics.

A review on recent advances towards sustainable development of bio-inspired agri-waste based cellulose aerogels

Cellulose aerogel (CA) is considered to be the most promising material due to its extraordinary properties like unique microstructure, porosity, large specific surface area, biodegradability, renewable nature and lightweight. Cellulosic aerogels are thus found to have potential applications in different fields especially in water purification and biomedical field. Agricultural waste based cellulose aerogels are recently getting wider attention owing to its sustainability. The synthesis methods of agri-waste based cellulose aerogels, its properties and application in different fields especially in the field of water purification are detailed in a comprehensive manner. This review tries to bring light into the commercialization of value-added products from sustainable, cheap agricultural waste material and tries to motivate young researchers.

Application of protein/polysaccharide aerogels in drug delivery system: A review

Drug delivery systems have emerged as a prominent research focus in the field of drug development, offering enhanced stability and improved bioavailability. Among them, protein (silk, gelatin and whey) or polysaccharide (alginate, chitosan, cellulose, starch, pectin and carrageenan) aerogels derived from natural sources have gained increasing popularity due to their unique advantages, such as cost-effectiveness, flexible preparation, bioactivity, biocompatibility, and biodegradability. However, despite their growing significance, there remains a lack of comprehensive information and ongoing confusion regarding the application of protein/polysaccharide aerogels in drug delivery system. Hence, the objective of this review was to provide a comprehensive review of the research progress in protein/polysaccharide aerogels for drug delivery systems from the perspective of aerogels category, synthesis strategy, drug-loading method, performance characteristic and release mechanism. Furthermore, by consolidating the existing information, we aimed to present our own perspectives and insights on the future development of protein/polysaccharide aerogels in drug delivery system. In conclusion, this comprehensive review served as a valuable resource for researchers and scholars, addressing the current gaps in knowledge and clarifying the complex landscape of protein/polysaccharide aerogels in drug delivery system.

Aerogel-Based Biomaterials for Biomedical Applications: From Fabrication Methods to Disease-Targeting Applications

Aerogel-based biomaterials are increasingly being considered for biomedical applications due to their unique properties such as high porosity, hierarchical porous network, and large specific pore surface area. Depending on the pore size of the aerogel, biological effects such as cell adhesion, fluid absorption, oxygen permeability, and metabolite exchange can be altered. Based on the diverse potential of aerogels in biomedical applications, this paper provides a comprehensive review of fabrication processes including sol-gel, aging, drying, and self-assembly along with the materials that can be used to form aerogels. In addition to the technology utilizing aerogel itself, it also provides insight into the applicability of aerogel based on additive manufacturing technology. To this end, how microfluidic-based technologies and 3D printing can be combined with aerogel-based materials for biomedical applications is discussed. Furthermore, previously reported examples of aerogels for regenerative medicine and biomedical applications are thoroughly reviewed. A wide range of applications with aerogels including wound healing, drug delivery, tissue engineering, and diagnostics are demonstrated. Finally, the prospects for aerogel-based biomedical applications are presented. The understanding of the fabrication, modification, and applicability of aerogels through this study is expected to shed light on the biomedical utilization of aerogels.

Application of Nanocellulose-Based Aerogels in Bone Tissue Engineering: Current Trends and Outlooks

The complex or compromised bone defects caused by osteomyelitis, malignant tumors, metastatic tumors, skeletal abnormalities, and systemic diseases are difficult to be self-repaired, leading to a non-union fracture. With the increasing demands of bone transplantation, more and more attention has been paid to artificial bone substitutes. As biopolymer-based aerogel materials, nanocellulose aerogels have been widely utilized in bone tissue engineering. More importantly, nanocellulose aerogels not only mimic the structure of the extracellular matrix but could also deliver drugs and bioactive molecules to promote tissue healing and growth. Here, we reviewed the most recent literature about nanocellulose-based aerogels, summarized the preparation, modification, composite fabrication, and applications of nanocellulose-based aerogels in bone tissue engineering, as well as giving special focus to the current limitations and future opportunities of nanocellulose aerogels for bone tissue engineering.

Self-healing, antibacterial and anti-inflammatory chitosan-PEG hydrogels for ulcerated skin wound healing and drug delivery

Great efforts have been performed on the production of advanced biomaterials with the combination of self-healing and wound healing properties in implant/tissue engineering biomedical area. Inspired by this idea, chitosan (CHI) based hydrogels can be used to treat a less investigated class of harmful chronic wounds: ulcers or pressure ulcers. Thus, CHI was crosslinked with previously synthesized polyethylene glycol diacid (PEG-diacid) to obtain different CHI-PEG hydrogel formulations with high H-bonding tendency resulting in self-repair ability. Here presented results show biocompatible, antibacterial, anti-inflammatory, and self-healing CHI-PEG hydrogels with a promising future in the treatment of ulcerated wounds by a significant improvement in metabolic activity (94.51 ± 4.38 %), collagen and elastin quantities (2.12 ± 0.63 μg collagen and 4.97 ± 0.61 μg elastin per mg dermal tissue) and histological analysis. Furthermore, cefuroxime (CFX), tetracycline (TCN) and amoxicillin (AMX) antibiotics, and acetylsalicylic acid (ASA) anti-inflammatory agent were sustainedly released for enhancing antibacterial and anti-inflammatory activities of hydrogels.

Aerogels as promising materials for antibacterial applications: a mini-review

The increasing cases of bacterial infections originating from resistant bacteria are a serious problem globally and many approaches have been developed for different purposes to treat bacterial infections. Aerogels are a novel class of smart porous materials composed of three-dimensional networks. Recently, aerogels with the advantages of ultra-low density, high porosity, tunable particle and pore sizes, and biocompatibility have been regarded as promising carriers for the design of delivery systems. Recently, aerogels have also been provided with antibacterial activity through loading of antibacterial agents, incorporation of metal/metal oxides and via surface functionalization and coating with various functional groups. In this mini-review, the synthesis of aerogels from both conventional and low-cost precursors is reported and examples of aerogels displaying antibacterial properties are summarized. As a result, it is clear that the encouraging antibacterial performance of aerogels promotes their use in many antibacterial applications, especially in the food industry, pharmaceutics and medicine.

Effect of Cellulose Characteristics on the Properties of the Wet-Spun Aerogel Fibers

Cellulose aerogels (CAs) from plant or bacterial-derived cellulose have advantages such as low density, high porosity, and high specific surface area and have been used in various applications including biomedical fields. One limiting factor in developing CAs is their demanding shaping process since it involves several steps of dissolution/dispersion of cellulose, geometry configurations using molds or nozzles, coagulation and washing of the gel body, and drying techniques. CA fibers can be converted into textiles and enhance the design ability, stiffness, and flexibility of the CAs. This study aims to understand the correlations between the initial cellulose characteristics, aerogel’s internal structure, and its prospective biomedical application. Wet-spun CA fibers were obtained by supercritical CO2 drying from low and high molecular weight microcrystalline cellulose in calcium thiocyanate tetrahydrate solution. Fiber spinning, thermal behavior, textural properties, and biological assessments of the CA fibers were inspected. The CA microfibers from high molecular weight cellulose proved to have a higher surface area (~197 m2/g), denser structure, and finer nanofibrils (~2 nm) with better thermal stability in comparison with the fibers produced from low molecular weight cellulose. The fibers were nontoxic, and cell proliferation was observed over time. CA fibers showed promising results to be used for biomedical applications such as tissue engineering and wound care.

Preparation of aerogel beads and microspheres based on chitosan and cellulose for drug delivery: A review

Spherical aerogels are not easily broken during use and are easier to transport and store which can be used as templates for drug delivery. This review summarizes the possible approaches for the preparation of aerogel beads and microspheres based on chitosan and cellulose, an overview to the methods of manufacturing droplets is presented, afterwards, the transition mechanisms from sol to a spherical gel are reviewed in detail followed by different drying processes to obtain spherical aerogels with porous structures. Additionally, a specific focus is given to aerogel beads and microspheres to be regarded as drug delivery carriers. Furthermore, a core/shell architecture of aerogel beads and microspheres for controlled drug release is described and subjected to inspire readers to create novel drug release system. Finally, the conclusions and outlooks of aerogel beads and microspheres for drug delivery are summarized.

Production of Bacterial Cellulose Aerogels With Improved Physico-Mechanical Properties and Antibacterial Effect

Aerogels have gained significant interest in recent decades because of their unique properties such as high porosity, low density, high surface area, and excellent heat and noise insulation. However, their high cost and low mechanical strength limit their practical application. We developed appropriate conditions to produce aerogels with controlled density, high mechanical strength, and thermal characteristics from bacterial cellulose (BC) synthesized by the strain Komagataeibacter sucrofermentans H-110. Aerogels produced using TEMPO oxidized BC (OBC) exhibited high mechanical strength and lower shrinkage than those from native bacterial cellulose (NBC). Compared to the NBC, the use of TEMPO-oxidized BC with oxidation degrees (OD) of 1.44 and 3.04% led to the reduction of shrinkage of the aerogels from 41.02 to 17.08%. The strength of the aerogel produced from the TEMPO-oxidized BC with an oxidation degree of 1.44% was twice that of the aerogel produced from NBC. The addition of Mg²⁺ at concentrations of 20 and 40 mM during the preparation of the aerogels increased the strength of the aerogels by 4.9 times. The combined use of TEMPO-oxidized BC and Mg²⁺ allowed pore size reduction from 1,375 to 197.4 μm on the outer part of the aerogels, thereby decreasing the thermal conductivity coefficient from 0.036 to 0.0176 W/(m•K). Furthermore, novel biocomposites prepared from the aerogels based on NBC and OBC and sodium fusidate, which have high antibiotic activity against Staphylococcus aureus, were obtained. Owing to their antibacterial properties, these aerogels can be used as functional biomaterials in a wide range of applications such as in tissue engineering and fabrication of wound dressing materials.

A Review on Revolutionary Natural Biopolymer-Based Aerogels for Antibacterial Delivery

A biopolymer-based aerogel has been developed to become one of the most potentially utilized materials in different biomedical applications. The biopolymer-based aerogel has unique physical, chemical, and mechanical properties and these properties are used in tissue engineering, biosensing, diagnostic, medical implant and drug delivery applications. Biocompatible and non-toxic biopolymers such as chitosan, cellulose and alginates have been used to deliver antibiotics, plants extract, essential oils and metallic nanoparticles. Antibacterial aerogels have been used in superficial and chronic wound healing as dressing sheets. This review critically analyses the utilization of biopolymer-based aerogels in antibacterial delivery. The analysis shows the relationship between their properties and their applications in the wound healing process. Furthermore, highlights of the potentials, challenges and proposition of the application of biopolymer-based aerogels is explored.

Antibacterial Activity of Bacterial Cellulose Loaded with Bacitracin and Amoxicillin: In Vitro Studies

The use of bacterial cellulose (BC) in skin wound treatment is very attractive due to its unique characteristics. These dressings’ wet environment is an important feature that ensures efficient healing. In order to enhance the antimicrobial performances, bacterial-cellulose dressings were loaded with amoxicillin and bacitracin as antibacterial agents. Infrared characterization and thermal analysis confirmed bacterial-cellulose binding to the drug. Hydration capacity showed good hydrophilicity, an efficient dressing’s property. The results confirmed the drugs’ presence in the bacterial-cellulose dressing’s structure as well as the antimicrobial efficiency against Staphylococcus aureus and Escherichia coli. The antimicrobial assessments were evaluated by contacting these dressings with the above-mentioned bacterial strains and evaluating the growth inhibition of these microorganisms.

Egg source natural proteins LBL modified cellulose nanofibrous mats and their cellular compatibility

Natural-based nanocomposites are competitive and promising materials for biomedical applications due to their biocompatibility. Herein, a novel natural-based composite was fabricated by alternately depositing lysozyme (LY) and albumin egg (AE) on electrospun cellulose nanofibrous mats via layer-by-layer self-assembly (LBL) technology. To indicate the successful deposition process and investigate the variations of the mats during LBL process, the surface morphology, physical property, chemical composition, wetting behavior and thermal stability were systematically studied. The results showed that the surface morphology and composition of the mats were significantly influenced by LBL process, which further resulted in the variation of wetting behavior. Besides, the mechanical properties were enhanced after LBL modification. In addition, the LBL structured nanofibrous mats exhibited antibacterial activity and excellent biocompatibility with L929 fibroblasts. In brief, LY and AE coated LBL structured cellulose nanofibrous mats, especially the 15 bilayers coated mats, have considerably potential applications in the biomedical field.

Facile and Green Preparation of Pectin/Cellulose Composite Films with Enhanced Antibacterial and Antioxidant Behaviors

Novel bioactive films based on pectin and cellulose (PC) with different loadings of tea polyphenols and cinnamaldehyde were successfully prepared. A thermal stability was tested, and the results showed that the thermal stability decreased slightly after loading with cinnamaldehyde and tea polyphenols, compared to PC films. The antimicrobial and antioxidant capacities were also investigated. Results showed that PC composite films had good DPPH radical and hydroxyl radical scavenging activities and excellent antibacterial activities against Escherichia coli, Candida albicans and Staphylococcus aureus. Based on the results, the great antioxidant and antibacterial activities of the tea polyphenol and cinnamaldehyde loaded PC films make them suitable for food packaging and preservation.