Applications of Bacterial Cellulose in Food, Cosmetics and Drug Delivery

Bacterial cellulose (BC) is a versatile biopolymer with better material properties, such as purity, high degree of porosity, relative high permeability to liquid and gases, high water-uptake capacity, tensile strength and ultrafine network. This review explores the applications of BC and its hydrogels in the fields of food, cosmetics and drug delivery. Applications of BC in foods are ranging from traditional dessert, low cholesterol diet, vegetarian meat, and as food additive and dietary aid to novel applications, such as immobilization of enzymes and cells. Applications in cosmetics include facial mask, facial scrub, personal cleansing formulations and contact lenses. BC for controlled drug delivery, transdermal drug delivery, dental drug delivery, protein delivery, tissue engineering drug delivery, macromolecular prodrug delivery and molecularly imprinted polymer based enantioselective drug delivery are also discussed in this review. The applications of BC in food and cosmetics provide the basis for BC-based functional foods, nutraceuticals, cosmeceuticals and medicated cosmetics. On the basis of current studies, the BC-based drug delivery could be further fine-tuned to get more sophisticated control on stimuli-responsive drug release. Along with the currently available literature, further experiments are required to obtain a blueprint of drug in vivo performance, bioavailability and in vitro–in vivo correlation.Peer reviewe

Current Trends in the Production of Cellulose Nanoparticles and Nanocomposites for Biomedical Applications

The goal of this chapter is to review the most recent trends to produce cellulose nanoparticles and nanocomposites with biomedical applications. These particles could be named as bacterial cellulose, cellulose nanofibers, and cellulose nanocrystals. The production of these nanoparticles with diameters below 100 nm is challenging because of the strong agglomeration tendency which occur upon drying aqueous cellulose suspensions or during the compounding process with hydrophobic polymers. Typically, the physical and mechanical properties of these nanoparticles depend on the source of cellulose and the extraction process employed. Cellulose nanoparticles are obtained by mechanical, chemical, or enzymatic process treatments to open the structure of the cellulose source and facilitate accessibility to its microstructure. Usually, a combination of these processes makes the extraction more efficient

Cellulose - Chitosan Nanocomposites - Evaluation of Physical, Mechanical and Biological Properties

This research describes the preparation of membranes with chitosan (CS) as the polymeric matrix and cellulose nanocrystals (CNC) as reinforcement. The aim was to evaluate their physical, mechanical and biological properties, and to determine their potential for biomedical use. Membranes were prepared via casting CNC suspensions in CS solution, at CNC concentrations of 0.5%, 1.0% and 2.0% (w/w) with pure chitosan as a reference. Analysis of membrane properties was performed using several techniques, such as ATR – FTIR, SEM, swelling test, maximum water absorption, dynamical mechanical analysis and in vivo (Winstar rats) biocompatibility and biodegradability assays for biological evaluation. Experimental results established that CNC reduced swelling rates and increased the maximum water absorption when CNC concentration was higher. Therefore, the presence of CNC in the matrix reduced Young’s modulus by approximately 50% in comparison with pure chitosan. All formulations demonstrated biocompatibility and biodegradability values ranged between 4% and 21% in the 30 days after implantation. Based on these results, these membranes may be of use for biomedical applications

Additive manufacturing of sustainable biomaterials for biomedical applications

Biopolymers are promising environmentally benign materials applicable in multifarious applications. They are especially favorable in implantable biomedical devices thanks to their excellent unique properties, including bioactivity, renewability, bioresorbability, biocompatibility, biodegradability, and hydrophilicity. Additive manufacturing (AM) is a flexible and intricate manufacturing technology, which is widely used to fabricate biopolymer-based customized products and structures for advanced healthcare systems. Three-dimensional (3D) printing of these sustainable materials is applied in functional clinical settings including wound dressing, drug delivery systems, medical implants, and tissue engineering. The present review highlights recent advancements in different types of biopolymers, such as proteins and polysaccharides, which are employed to develop different biomedical products by using extrusion, vat polymerization, laser, and inkjet 3D printing techniques in addition to normal bioprinting and four-dimensional (4D) bioprinting techniques. This review also incorporates the influence of nanoparticles on the biological and mechanical performances of 3D-printed tissue scaffolds. This work also addresses current challenges as well as future developments of environmentally friendly polymeric materials manufactured through the AM techniques. Ideally, there is a need for more focused research on the adequate blending of these biodegradable biopolymers for achieving useful results in targeted biomedical areas. We envision that biopolymer-based 3D-printed composites have the potential to revolutionize the biomedical sector in the near future

Técnicas de fermentación y aplicaciones de la celulosa bacteriana: una revisión

Bacterial cellulose is a polymer obtained by fermentation with microorganisms from Acetobacter, Rhizobium, Agrobacterium and Sarcina genera. Amongthem, Acetobacter xylinum is the most efficient specie. This polymer has the same chemical composition of plant cellulose, but its conformation and physicochemical properties are different, making it attractive for several applications, especially in the areas of food, separation processes, catalysis and health, due to its biocompatibility. However, the main problem is the production in mass that is constrained by low yield. It is therefore necessary to develop some alternatives. This paper presents a review about synthesis, production, properties and principal applications of bacterial cellulose, as well as some alternatives to reduce the difficulties for process scaling.La celulosa bacteriana es un polímero obtenido por fermentación con microorganismos de los géneros Acetobacter, Rhizobium, Agrobacterium y Sarcina. Entre ellos, Acetobacter xylinum es la especie más eficiente. Este polímero tiene la misma composición química de la celulosa vegetal, pero su conformación y propiedades fisicoquímicas son diferentes, lo que lo hace atractivo para varias aplicaciones, especialmente en las áreas de alimentos, procesos de separación, catálisis y salud, debido a su biocompatibilidad. Sin embargo, el principal problema es la producción en masa que está limitada por el bajo rendimiento. Por lo tanto, es necesario desarrollar algunas alternativas. Este artículo presenta una revisión sobre síntesis, producción, propiedades y principales aplicaciones de la celulosa bacteriana, así como algunas alternativas para reducir las dificultades para el escalado del proceso

Progenitor cells in auricular cartilage demonstrate promising cartilage regenerative potential in 3D hydrogel culture

The reconstruction of auricular deformities is a very challenging surgical procedure that could benefit from a tissue engineering approach. Nevertheless, a major obstacle is presented by the acquisition of sufficient amounts of autologous cells to create a cartilage construct the size of the human ear. Extensively expanded chondrocytes are unable to retain their phenotype, while bone marrow-derived mesenchymal stromal cells (MSC) show endochondral terminal differentiation by formation of a calcified matrix. The identification of tissue-specific progenitor cells in auricular cartilage, which can be expanded to high numbers without loss of cartilage phenotype, has great prospects for cartilage regeneration of larger constructs. This study investigates the largely unexplored potential of auricular progenitor cells for cartilage tissue engineering in 3D hydrogels

Small-animal SPECT/CT and nanofibrillar cellulose hydrogels : a preclinical evaluation of a potential novel biomaterial application

Cellulose has already been used as an industrial raw material for over a century. However, during recent years the nanostructural features of the naturally occurring biopolymer have been fully investigated and characterized through different processing methods as nanofibrillar cellulose (NFC). This has led to a rapid development of novel cellulose based nanoscale materials and advancements in the field of composite materials. NFC offers interesting specific properties that differ from many other natural and synthetic polymers, such as self-renewable raw materials, semi-crystalline morphology, broad chemical modification capacity, biocompatibility and biodegradability. Biocompatibility and the biomimetic aspects of NFC have enabled the fabrication of nanoporous membranes and scaffolds that can function as medical devices (e.g. tissue engineering, wound healing, novel active implants). In this study, the properties of plant-derived NFC, as potential injectable drug releasing hydrogel "implants" were investigated. Three different sized candidate molecules were selected (123I-NaI, 123I-β-CIT and 99mTc-HSA, from small to large respectively) and investigated with the use of a small animal SPECT/CT molecular imaging device. Study compounds were mixed with the NFC biomaterial and injected into the pelvic region of mice. Drug release was observed for a period of 24 hours and the results were compared to saline/study compound control injections. In addition, 99mTc labeled NFC hydrogels were prepared for dual label tracing to observe the hydrogel positioning during the SPECT/CT acquisitions. For the smaller compounds (123I-NaI, 123I-β-CIT), no differences were found in the drug release or absorption in between the NFC biomaterial and saline injections. However, a clear difference was found with the large compound (99mTc-HSA). In the NFC hydrogel, the rate of release was slower and the distribution of 99mTc-HSA was more concentrated around the area of injection. In addition, the NFC hydrogel did not migrate from, or disintegrate, at the site of injection, suggesting a robust enough structural integrity to withstand normal movement and activity. In conclusion, the labeling of NFC was found to be a reliable and simple method. NFC hydrogels have the potential use as drug releasing medical devices with larger compounds. NFC matrix did not have any controlled release effect on the studied small molecules. Therefore further studies are required for more specific conclusions.Selluloosa on uusiutuva luonnonvara, jota on käytetty teollisuuden raaka-aineena jo useita vuosikymmeniä. Nykyään raakamateriaalien uusien käsittelymenetelmien ansiosta, myös selluloosan nanorakenteiden ominaisuuksia on päästy tutkimaan. Tämä on johtanut uudenlaisten selluloosajohdannaisten, kuten fibrilliselluloosan, kehittymiseen. Fibrilliselluloosa on ominaisuuksiltaan kemiallisesti helposti muokattavissa, bioyhteensopiva, biohajoava ja morfologialtaan osittain kiteinen. Lisäksi raakamateriaalina, selluloosan lähteet luonnossa on lähes ehtymättömät. Useista synteettisistä ja muista luonnon polymeereistä poiketen, fibrilliselluloosasta on valmistettu nanohuokoisia membraaneja ja fysiologisia rakenteita muistuttavia hydrogeelejä, joita on onnistuneesti käytetty lääkinnällisinä laitteina (kudosteknologia, haavan hoito, aktiivi-implantit). Tämän työn tarkoituksena oli tutkia fibrilliselluloosaa injektoitavana, lääkeainetta vapauttavana "implanttina". Kolme molekyyliä valittiin edustamaan erikokoisia lääkeaineita (123I-NaI, 123I-β-CIT ja 99mTc-HSA). Fibrilliselluloosaimplantin toimivuutta tutkittiin SPECT/CT pieneläin kuvantamislaitteella. Tutkittavat molekyylit sekoitettiin fibrilliselluloosa hydrogeeliin ja injektoitiin ihonalaisesti hiirten lantion seudulle. Lääkeaineen vapautumista seurattiin 24 tunnin ajan, ja tuloksia verrattiin tutkittavien lääkeaineiden suolaliuosinjektioihin. Lisäksi kaksoiskuvantamista varten hydrogeeli leimattiin 99mTc:lla, jotta implantin sijaintia voitaisiin tarkkailla kuvantamisen ajan. Pienten molekyylien vapautumisessa (123I-NaI, 123I-β-CIT) ei havaittu eroja hydrogeeli- ja suolaliuosinjektioiden välillä. Ison molekyylin (99mTc-HSA) vapautumisessa ero oli kuitenkin huomattava. Vapautumisen nopeus oli hydrogeelistä hitaampaa, ja lääkeaine oli keskittynyt injektioalueelle, eikä jakautunut ihonalaiskudokseen kuten suolaliuosinjektioissa. Fibrilliselluloosa ei ollut kulkeutunut pois tai hajonnut injektioalueella koko kuvantamisen aikana, joten se on rakenteeltaan riittävän kestävä sietääkseen normaalia liikkumista ja toimintaa. Fibrilliselluloosan leimaus osoittautui luotettavaksi ja yksinkertaiseksi menetelmäksi. Injektoitava hydrogeeli on mahdollisesti tehokas lääkeainetta hallitusti vapauttava implantti isommille lääkeaineille, kuten proteiinit tai petidit. Eri lääkeaineiden tarkkailu vaatisi kuitenkin jatkotutkimuksia, jotta johtopäätöksiä voitaisiin tarkentaa

Aortic and pulmonary bioprosthetic heart valves: an insight on glycosaminoglycan distribution and fine structure in decellularized porcine scaffolds for tissue engineering purposes

Cardiac valves are dynamic structures, that remodel in response to changes in local mechanical forces, and exhibit a complex architecture highly specialized, consisting of cells and extracellular matrix enriched in proteoglycans, glycosaminoglycans (GAGs), collagen and elastic fibers. Typical valve substitutes are mechanical prostheses and bioprostheses. During the last 15 years, tissue engineering (TE) approaches emerged in response to limitations associated to valve bioprostheses. This study was designed to identify the specific GAGs in the leaflet and commissure of aortic and pulmonary valves and to interpret their maintenance in relation to a decellularization procedure finalized to obtain a scaffold for cell repopulation. Free GAGs were obtained from selected portions of leaflets, sinuses, and artery wall from 24 porcine valves freed from proteins by papain treatment. GAG content and distribution were assessed on both fresh and decellularized specimens. GAG structural analysis was performed after depolimerization and fluorescent derivatization of the products. The disaccharide analysis was conducted by fluorophore-assisted polyacrilamide gel electrophoresis (FACE). Results obtained show that total GAG concentration was reduced after decellularization and that the loss mainly regards hyaluronan and an undersulphate condroitin sulfate isomer. The functional consequence of this selective depletion on cell repopulation potential of the scaffold deserves further studies