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This paper presents a new way to obtain collagen/hydroxyapatite (COLL/HA) composite materials by 3D printing. Because of high tendency of segregation of COLL/HA composite materials, printing was done using COLL/Ca2+ gel (even COLL/Ca(OH)2) followed by precipitation of HA and crosslinking of COLL. The HA precipitation occurs simultaneously with crosslinking of COLL molecules, these processes being assured by the presence of glutaraldehyde supplemented PBS solution. By printing with COLL/Ca2+ at acidic pH homogeneity was increased. FTIR spectroscopy and microscopy reveal HA formation as the main inorganic phase these nanoparticles being homogeneously dispersed in the volume. In vitro biocompatibility assays were performed on Vero cells (ISO10993-5/2009). Results show that the extract of the developed biomaterial in cell culture medium elicited a similar cellular response to standard culture medium demonstrating its potential for biomedical applications. The described procedure and proposed ink can be used for developing 3D bone scaffolds and open new perspectives for COLL/Ca2+ homogeneous inks.

Compared to the classical systemic administration, the local drug release has some advantages, such as lack of systemic toxicity and associated side effects, increased patient compliance, and a low rate of bacterial resistance. Biopolymers are widely used to design sustained drug delivery systems and biomaterials for tissue engineering. Type II collagen is the indispensable component in articular cartilage and plays a critical role in the growth and proliferation process of chondrocytes. Thus, type II collagen has drawn more attention and interest in the treatment and research of the cartilage regeneration. The aim of this study was to obtain, characterize, and optimize the microcapsules formulation based on type II collagen, sodium alginate, and sodium carboxymethyl cellulose loaded with doxycycline as an antibiotic model drug that could be incorporated further in hydrogels to improve the localized therapy of septic arthritis. The new synthesized microcapsules were assessed by spectral (FT-IR), morphological (optical microscopy), and biological analysis (enzymatic biodegradation, antimicrobial activity). The size distribution of the obtained microcapsules was determined using optical microscopy. The drug encapsulation efficiency was also determined. To optimize the microcapsules&rsquo, composition, some physical-chemical and biological analyses were subjected to an optimization technique based on experimental design, response surface methodology, and the Taguchi technique, and the adequate formulations were selected. The results obtained recommend these new microcapsules as promising drug systems to be further incorporated in type II collagen hydrogels used for septic arthritis.

Lavandula angustifolia which belong to Lamiaceae family with origins in the Mediterranean regionis one of the most important species of Lavandula. The most common method for obtaining the essential oil of lavender is described in the literature is steam hydrodistillation using a Neo-Clevenger, official method described in the European Pharmacopoeia. Another method described in the literature for obtaining oil of lavender is the extraction using microwave. The aim of this study was to obtain lavender essential oils bythese two different methods: classical hydrodistillation using Neo-Clevenger apparatus and microwave�assisted extraction. The yield of extraction was different for the two of methods 0.124 % for classical hydrodistillation and 0.6 % for microwave � assisted extraction. In order to establish and compare the chemical composition of lavender essential oils we used a gas chromatography coupled with mass spectrometry (GC-MS). In the classical hydrodistillation method 44 components with 99.20% yield and in microwave extraction, 46 components with 99.33% yields have been identified. The main compound of essential oil obtained was Linalool. But the other secondary main components are totally different. Even if the obtainedyield for lavender essential oil was bigger in the case of classical hydrodistillation, taking into account the time of extraction was lower for the oil obtained by microwave, it is recommended to continue with this modern method.

The present work targets the development of collagen-based hydrogel precursors, functionalized with photo-crosslinkable methacrylamide moieties (COL-MA), for vascular tissue engineering (vTE) applications. The developed materials were physico-chemically characterized in terms of crosslinking kinetics, degree of modification/conversion, swelling behavior, mechanical properties and in vitro cytocompatibility. The collagen derivatives were benchmarked to methacrylamide-modified gelatin (GEL-MA), due to its proven track record in the field of tissue engineering. To the best of our knowledge, this is the first paper in its kind comparing these two methacrylated biopolymers for vTE applications. For both gelatin and collagen, two derivatives with varying degrees of substitutions (DS) were developed by altering the added amount of methacrylic anhydride (MeAnH). This led to photo-crosslinkable derivatives with a DS of 74 and 96% for collagen, and a DS of 73 and 99% for gelatin. The developed derivatives showed high gel fractions (i.e. 74% and 84%, for the gelatin derivatives; 87 and 83%, for the collagen derivatives) and an excellent crosslinking efficiency. Furthermore, the results indicated that the functionalization of collagen led to hydrogels with tunable mechanical properties (i.e. storage moduli of [4.8–9.4 kPa] for the developed COL-MAs versus [3.9–8.4 kPa] for the developed GEL-MAs) along with superior cell-biomaterial interactions when compared to GEL-MA. Moreover, the developed photo-crosslinkable collagens showed superior mechanical properties compared to extracted native collagen. Therefore, the developed photo-crosslinkable collagens demonstrate great potential as biomaterials for vTE applications.

A lot of biomaterials were investigated as suitable scaffolds for wound healing, very high costs being involved for treating their complications and consequences. Among them, a special attention is given to collagen, a natural biopolymer which showed positive effect on soft tissue regeneration. A key factor encountered in wound healing is represented by the pain control. Thus, the purpose of this study was to design and characterize some 3D composites based on collagen and lidocaine hydrochloride as anesthetic drug model with analgesic properties. Type I fibrillar collagen gel (1.40% w/w, 3.5 pH) was extracted from calf hide by the technology currently used in Collagen Department of Division Leather and Footwear Research Institute. The collagen composites were obtained by freeze-drying of gels adjusted at 1% and 7.2 pH, with different sodium carboxymethylcellulose (NaCMC) (0; 20 and 40%) concentrations (reported to dry gel), with 0.5% and without lidocaine, un-and crosslinked with glutaraldehyde (0.5% reported to collagen dry substance). The 3D composites were evaluated through water absorption, FT-IR spectroscopy, and enzymatic degradation. The in vitro release of lidocaine from the tested formulations was performed using a sandwich device adapted to a dissolution equipment. A typical biphasic drug release profiles was recorded, with an important lidocaine burst release effect in the first minutes, ensuring a rapid pain diminution, followed by a prolonged release over next hours. The lidocaine release from the designed formulations showed an anomalous drug transport kinetic mechanism. The composites showed a porous structure, proper swelling behaviour for wound exudates and degradation in time. The collagen-NaCMC-based composites could be a promising solution in wound healing management.

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen-hydroxyapatite/barium titanate (Coll-HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol-gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll-HA and Coll-HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll-HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT.

The goal of this paper was the design, development, and characterization of some new composites, based on collagen and dextran as natural polymers and zinc oxide as antimicrobial, to be used in wound healing. Collagen hydrogels with various concentrations of dextran and zinc oxide were investigated in terms of rheological analysis. The spongious composites, obtained by freeze-drying of hydrogels, were evaluated by morphology (SEM), water uptake, and biological (enzymatic biodegradation) analysis. All the results were strongly influenced by the nature and concentration of composite components. Based on the performances of the hydrogels, stationary rheometry, porous structure, morphology, and biological behavior, the antimicrobial spongious composite based on collagen and dextran with 50% ZnO were the most promising for future applications in wound dressing and a biomaterial with high potential in skin regeneration.

In this work, we investigate for the first time several issues involved in bio-adhesion process for a new type of chemically modified titanium surfaces (in their initial form and after collagen deposition), in order to assess their potential in dental implant surface modification. For this purpose, we studied the following: collagen adhesion, cytotoxicity, osteoblast cytomorphology, cell adhesion and proliferation, doxycycline embedding and modifications in the collagen film deposed on the metal surfaces, drug release from the collagen films. The improvement of adhesion between collagen film and titanium substrate, when hydroxyl and amino functional groups are assisting the surfaces was presented, all materials showing no cytotoxic effects as revealed by lactate dehydrogenase-based assay. The drug release from titanium–coll–doxy systems offers a dual mechanism of the delivery profile (burst release followed by moderate discharge of the antibiotic), with perspectives in soft tissue recovery postoperative s...

This paper aims at demonstrating the biocompatibility of recently developed 3D hydrogel scaffolds containing the same amount of collagen (COLL) and variable concentrations of sericin (SS) in order to find the most suitable formula for adipose tissue engineering (ATE) applications. These scaffolds were obtained by COLL crosslinking with glutaraldehyde followed by freeze-drying and, subsequently, seeded with 3T3-L1 preadipocytes. Scanning electron microscopy studies revealed the scaffolds׳ architecture and cellular colonization. Also, in vitro biocompatibility of the developed scaffolds was evaluated by LDH and MTT assays and Live/Dead analysis of 3T3-L1 preadipocyte populating these 3D matrices. The best results in terms of cell survival and proliferation status were obtained in the case of the hybrid COLL scaffold containing 40% SS (COLL–SS4). Furthermore, the biological performance of the analyzed COLL-based hydrogels at 5- and 8- days post-seeding was found to decrease as follows: COLL–SS4>COLL–SS2>COLL>COLL–SS6. Consequently, our study highlights that hybrid scaffolds obtained by the addition of variable concentrations of SS to a constant COLL composition positively influences the behavior of 3T3-L1 cells with the exception of the COLL–SS6 matrix (60% SS). Altogether, the data obtained recommend SS as a component of COLL-based hydrogels providing them with features that may be useful in ATE applications.

The paper describes the preparation, characterisation, and testing of tetracycline loaded collagen-carboxymethylcellulose/hydroxyapatite ternary composite materials. The synthesis of this drug delivery system consists in two steps: the first step is the mineralization of collagen-carboxymethylcellulose gel while the second step corresponds to the loading of the ternary composite material with tetracycline. The obtained DDS is characterised by physicochemical, morphological, and release behaviour by using FTIR spectroscopy and microscopy, scanning electron microscopy, and UV-VIS spectroscopy. Based on the release study, it can be assumed that tetracycline is released in a prolonged way, assuring at least 6 days of antiseptic properties.

Bone regeneration is a serious challenge in orthopedic applications because of bone infections increase, tumor developing, and bone loss due to trauma. In this context, the aim of our study was to develop innovative biomaterials based on collagen and hydroxyapatite (25, 50, and 75%) which mimic bone composition and prevent or treat infections due to doxycycline content. The biomaterials were obtained by freeze-drying in spongious forms and were characterized by water uptake capacity and microscopy. Thein vitrorelease of doxycycline was also determined and established by non-Fickian drug transport mechanism. Among the studied biomaterials, the most suitable one to easily deliver the drug and mimic bone structure, having compact structure and lower capacity to uptake water, was the one with 75% hydroxyapatite and being cross-linked.

The aim of this chapter is to discuss the advances in the field of soft tissue engineering highlighting the advantages of the use of drug delivery systems instead of pure, regenerative grafts. Tissue engineering evolved dramatically, from natural occurring materials to cell-seeded and drug-loaded engineered materials, from macro- to micro- and nanoscale. It is most important to mention the evolution from the last century because this is the period when, based on scientific approaches, the outcomes became exponential. From an evolutionary point of view, both pure regenerative as well as the drug-loaded systems are now studied, in preclinical and clinical phases. In fact, these two general classes of systems should be studied together because the properties of the drug-loaded systems are strongly dependent on the support characteristics. In the field of soft tissue engineering, some materials are intensively studied: chitosan and its derived materials; collagen and gelatin, polyvinyl alcohol, polycaprolactone, etc. The recent advances in this field are related to the active components which are used for loading these materials in order to improve or even induce new properties/functionalities. Special attention over recent decades has been devoted to the faster healing, antimicrobial and antitumoral activity of these materials and, consequently, this chapter is mainly devoted to these aspects.

Superporous materials based on two proteins, collagen and sericin were synthesized by freeze-drying considering various ratios between the two proteins. To evaluate the influence of sericin content on the structure/properties relationship, the obtained scaffolds were further characterized using spectroscopic analysis, thermal, and mechanical techniques. Scanning electron microscopy was used to investigate the morphological structure of the scaffolds and the swelling properties as well as the stability of the scaffolds were also assessed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

In the past years an increased interest to create new polymeric blends with application in the medical area for development of new types of biomaterials has appeared. Electron beam irradiation is well known as a method of producing important changes in polymer structure, being an alternative to chemical synthesis of biomaterials based on polymeric materials. The aim of the present study was to investigate the behaviour of some polyvinylpyrrolidone-dextran (PVP/DEX) blends under electron beam irradiation. Aqueous solutions of PVP with molecular weights of 360 000 Da (PVP 360), 40 000 Da (PVP 40), and DEX with molecular weight of 500 000 Da (DEX), were mixed as to obtain 50:50 blends of PVP40/DEX and PVP360/DEX. The obtained blends were irradiated with electron beam at different radiation doses and after irradiation treatment were processed by freeze-drying. PVP/DEX blends were characterized by infrared spectroscopy (FT-IR) and thermal analysis. The analyses were conducted in order to establish the relation between radiation dose and changes of structural and thermal properties.

The aim of this study was the development of biocomposite scaffolds (membranes and matrices) based on natural polymers used for bone tissue engineering. The novelty featured in this paper is the use of phosphorylated dextran (PDex) as natural component in collagen-based biocomposites. The PDex both in acid form and as mixed salts of Mg–Na, Zn–Na, Ca-Na was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, potentiometric and conductometric titration and energy dispersive x-ray spectroscopy (EDX) analysis. The biocomposite scaffolds were obtained by freeze-drying as matrices and by free-drying as membranes with specific microporous morphological structures that depended on drying process of collagen gels with PDex. The biocomposites were physical–chemical characterized by differential scanning calorimetry (DSC) and, water and water vapor absorption. The biocompatibility was evaluated in vitro with human osteosarcoma MG 63 cell lines. The results showed that biocompatibility was improved by the use of PDex as mixed salts of Mg–Na, Zn–Na, Ca-Na in collagen biocomposites.

In this paper it is proposed a new method of encapsulation of oregano essential oil (EO) into carbon nanotubes, singlewalled (SWCNTs) and multiwalled (MWCNTs). Multiwalled carbon nanotubes were functionalized by oxidation methods to obtain carboxilated carbon nanotubes MWCNT-COOH and aminated carbon nanotubes MWCNT-NH2. The effect of encapsulating matrix on protection and delivery of oregano essential oil was studied. We will refer to preparation by encapsulation of carbon nanotubes with oregano essential oil in order to improve characteristics that can be used in biomedical applications. EO was encapsulated in carbon nanotubes by physical immersion and the samples were ultrasonated for 2 hours at 37oC. After the treatment of carbon nanotubes with oregano essential oil, these varieties of materials were inserted into a collagen gel and lyophilized in order to obtain collagen matrices. The structure of the new functionalized carbon nanotubes immersed in a collagen matrix was identified using infrared spectroscopy (FTIR analysis) and morphological features were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM).

This paper presents the synthesis, characterisation, andin vitrotesting of homogenous and heterogeneous materials containing silver nanoparticles (nanoAg). Three types of antiseptic materials based on collagen (COLL), hydroxyapatite (HA), and collagen/hydroxyapatite (COLL/HA) composite materials were obtained. The synthesis of silver nanoparticles was realized by chemical reaction as well as plasma sputtering deposition. The use of chemical reduction allows the synthesis of homogenous materials while the plasma sputtering deposition can be easily used for the synthesis of homogeneous and heterogeneous support. Based on thein vitroassays clear antiseptic activity againstEscherichia coliwas relieved even at low content of nanoAg (10 ppm).

Development of bioactive material template for in vitro and in vivo synthesis of osteoinductive and biodegradable bone material was intensevely studied over the last decade and the research in the ...