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The fabrication of collagen-based biomaterials for skin regeneration offers various challenges for tissue engineers. The purpose of this study was to obtain a novel series of composite biomaterials based on collagen and several types of clays. In order to investigate the influence of clay type on drug release behavior, the obtained collagen-based composite materials were further loaded with gentamicin. Physiochemical and biological analyses were performed to analyze the obtained nanocomposite materials after nanoclay embedding. Infrared spectra confirmed the inclusion of clay in the collagen polymeric matrix without any denaturation of triple helical conformation. All the composite samples revealed a slight change in the 2-theta values pointing toward a homogenous distribution of clay layers inside the collagen matrix with the obtaining of mainly intercalated collagen-clay structures, according X-ray diffraction analyses. The porosity of collagen/clay composite biomaterials varied depending on clay nanoparticles sort. Thermo-mechanical analyses indicated enhanced thermal and mechanical features for collagen composites as compared with neat type II collagen matrix. Biodegradation findings were supported by swelling studies, which indicated a more crosslinked structure due additional H bonding brought on by nanoclays. The biology tests demonstrated the influence of clay type on cellular viability but also on the antimicrobial behavior of composite scaffolds. All nanocomposite samples presented a delayed gentamicin release when compared with the collagen-gentamicin sample. The obtained results highlighted the importance of clay type selection as this affects the performances of the collagen-based composites as promising biomaterials for future applications in the biomedical field.

Cosmetic area has increased worldwide and will continue to expand as long as there are users. At the moment, the interest leads towards cosmetics based on natural ingredients. A common aesthetic problem for majority of the people is represented by dark circles which appear in the infraorbital region. The purpose of this work was to prepare and analyze new cosmetics based on collagen and caffeine with antimicrobial activity that can be used for the treatment of dark circles. The obtained cosmetics are stable at the natural pH of the skin, indicating that new products can be securely used. Images from the optical microscopy evaluation revealed that cosmetics have a soft and foam like appearance. All the obtained cosmetics present excellent stability at 4 and 40°C. The antimicrobial activity against Staphylococcus aureus and Escherichia coli was also performed showing that the cream with collagen hydrolysate and smallest amount of caffeine is the most efficient Some more analysis need to be performed before notification.

The development of stem cell technology in combination with advances in biomaterials has opened new ways of producing engineered tissue substitutes. In this study, we investigated whether the therapeutic potential of an acellular porous scaffold made of type I collagen can be improved by the addition of a powerful trophic agent in the form of mesenchymal stromal cells conditioned medium (MSC‐CM) in order to be used as an acellular scaffold for skin wound healing treatment. Our experiments showed that MSC‐CM sustained the adherence of keratinocytes and fibroblasts as well as the proliferation of keratinocytes. Moreover, MSC‐CM had chemoattractant properties for keratinocytes and endothelial cells, attributable to the content of trophic and pro‐angiogenic factors. Also, for the dermal fibroblasts cultured on collagen scaffold in the presence of MSC‐CM versus serum control, the ratio between collagen III and I mRNAs increased by 2‐fold. Furthermore, the gene expression for α‐smooth muscle actin, tissue inhibitor of metalloproteinase‐1 and 2 and matrix metalloproteinase‐14 was significantly increased by approximately 2‐fold. In conclusion, factors existing in MSC‐CM improve the colonization of collagen 3D scaffolds, by sustaining the adherence and proliferation of keratinocytes and by inducing a pro‐healing phenotype in fibroblasts.

Brewing yeast biomasses may be converted into valuable products, including supplements for ruminant diets. This paper presents experimental data on a nutraceutical suspension formulation containing post-fermentation brewing yeasts and the brewing yeast strain, Saccharomyces pastorianus ssp. carlsbergensis W34/70, which was intended to be administered to ruminants. The brewing yeast biomass is a component of oral suspensions designed as dietary supplements that prevent digestive acidosis in ruminants. The brewing yeast strain W34/70 was cultivated using molasses (M) and glucose (G) as carbon sources and was lyophilized at different freezing temperatures (0�C, �10�C, �20�C, �30�C, and �40�C). The post-fermentation brewing yeast biomass was spray dried (AAY) and lyophilized (ALY). Both dried yeast biomasses were analyzed in terms of wettability using a contact angle (CA�) evaluation at the solid/liquid interface. Suspensions were subsequently formulated and tested. Their physical and aggregative stability was established in connection with controlled sedimentation and flocculation. The assays were performed following quality by design (QbD) principles. The critical process parameters (CPPs) corresponding to the technological process of yeast production, as well as the critical quality attributes (CQAs) for suspension formulations, were pointed out as preamble determinants when designing oral nutraceuticals destined to be included in ruminant diets.

Presently, notwithstanding the progress regarding wound-healing management, the treatment of the majority of skin lesions still represents a serious challenge for biomedical and pharmaceutical industries. Thus, the attention of the researchers has turned to the development of novel materials based on cellulose derivatives. Cellulose derivatives are semi-synthetic biopolymers, which exhibit high solubility in water and represent an advantageous alternative to water-insoluble cellulose. These biopolymers possess excellent properties, such as biocompatibility, biodegradability, sustainability, non-toxicity, non-immunogenicity, thermo-gelling behavior, mechanical strength, abundance, low costs, antibacterial effect, and high hydrophilicity. They have an efficient ability to absorb and retain a large quantity of wound exudates in the interstitial sites of their networks and can maintain optimal local moisture. Cellulose derivatives also represent a proper scaffold to incorporate various bioactive agents with beneficial therapeutic effects on skin tissue restoration. Due to these suitable and versatile characteristics, cellulose derivatives are attractive and captivating materials for wound-healing applications. This review presents an extensive overview of recent research regarding promising cellulose derivatives-based materials for the development of multiple biomedical and pharmaceutical applications, such as wound dressings, drug delivery devices, and tissue engineering.

The aim of this study was to formulate and evaluate two types of O/W emulsions based on collagen and other natural ingredients that can be used as color correcting (CC-cream) and cream foundation. Both types of emulsions obtained are stable at different temperatures and the pH values of emulsions correspond to the natural pH of the skin, indicating that emulsions can be safely applied to the skin. Results from the optical microscopy analysis show that all emulsions present foam-like appearance. The rheological properties of emulsions were studied and it was proved that all emulsions present a non-Newtonian pseudoplastic behaviour and thixotropic characteristics at two operating temperatures (24 and 33�C). It can be concluded that all emulsions can be used as a natural alternative to a CC-cream or a cream foundation. Further microbiological tests and clinical trials are necessary for the obtained emulsions.

The present study was focused on the preparation and characterization of different topical oil in water emulsions based on natural ingredients such as collagen hydrolysate and vegetable oils mixtures. As oil phases, mixtures of coconut, almond, jojoba, avocado oils (in different ratios) were used while the water phase consisted in lavender water. As emulsifier, a plant based product containing glyceryl stearate and potassium stearate was incorporated (in the concentration range 4–5 %), while as rheology modifier xanthan gum was used (in the concentration range 0.2–1 %). As preservatives, Cosgard (containing benzyl alcohol, salicylic acid, glycerol, ascorbic acid) and mixtures of two essential oils (lemon and lavender) were selected. The designed formulations were assessed by means of their physico-chemical properties (pH, viscosity, thixotropic behavior), optical microscopy analysis and sensorial characteristics. The obtained emulsions were found to present pseudoplastic and thixotropic behaviors, adequate for cosmetic skin care product formulations.

Depending on the concentration of the drug and/or the method of administration, drugs could be used in various ways. To take full advantage of the drug beneficial properties in oral medical interventions but also in other types of surgery, like plastic surgery, general surgery, or gynecological surgery, the drug concentration as well as the administration method itself will depend on the wound, type of surgery, and severity of the postoperative pain which can be very different. Generally, the local administration methods are recommended. Piroxicam, a nonsteroidal anti-inflammatory drug (NSAID) of the oxicam class, is generally used to relieve the symptoms of pain and inflammation. Starting from the idea of the special benefit of the interference between collagen-based materials and drug beneficial properties, our work was focused on the synthesis and characterization of new collagen-piroxicam materials. These new collagen-based materials present a good water absorption, and the piroxicam release suggests a biphasic drug release profile whereas the obtained values for the release exponent revealed a complex release mechanism including swelling, diffusion, and erosion.

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.

Staphylococcus epidermidis is a Gram-positive resident of the human skin, which in certain conditions, can turn into an opportunistic pathogen, being one of the most frequent agents of nosocomial infections, particularly of those associated with indwelling medical devices. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of two essential oils (EOs) to be used alone or in combination as natural alternatives to currently available antibiotics, for treating S. epidermidis infections or preventing the contamination and further development of S. epidermidis biofilm on viable tissues or medical devices. For this purpose C. limon and L. angustifolia EOs were obtained both by hydrodistillation and microwave-assisted extraction and analyzed by GC–MS. The compositions of EOs as a function of the extraction procedure were compared and discussed. Each of the two extraction techniques was more effective in the extraction of different components of the EOs. In the case of C. limon EOs, terpinen-4-ol, α-terpineol and linalool, not found in the microwave assisted extract, are obtained by classical hydrodistillation (being compounds of high polarity) while less polar compounds (α-pinene, β-pinene, limonene, γ-terpinene) are drawn into higher percentage through the microwave-assisted procedure. In the case of L. angustifolia EOs, a higher percentage of compounds with high polarity (such as linalool) is extracted by classical hydrodistillation while the compounds with lower polarity, such as acetates (linalyl acetate and neryl acetate) are extracted in higher proportion by the microwave-assisted extraction method. The antibacterial and antibiofilm effects of the EOs and of their mixtures were tested towards five S. epidermidis clinical strains and their biological activity was correlated with the oils composition. The most active composition was represented by the binary mixture (1:1) of the EOs obtained by hydrodistillation, containing terpene alcohols (such linalool) and d -limonene, which exhibited the lowest minimum inhibitory concentration (3.9 μg/mL) and minimum biofilm eradicating concentration (0.97–7.81 μg/mL), against all tested S. epidermidis strains. Other minor constituents, such as terpinen-4-ol, α-terpineol, linalyl acetate, neryl acetate, geranyl acetate and α-pinene could be potentiated in presence of limonene and could be responsible for the high antimicrobial activity of these EOs mixture.

Microbial infections associated with skin diseases are frequently investigated since they impact on the progress of pathology and healing. The present work proposes the development of freeze-dried, glutaraldehyde cross-linked, and non-cross-linked biocomposite dressings with a porous structure, which may assist the reepithelization process through the presence of collagen and carboxymethylcellulose, along with a therapeutic antimicrobial effect, due to silver nanoparticles (AgNPs) addition. Phisyco-chemical characterization revealed the porous morphology of the obtained freeze-dried composites, the presence of high crystalline silver nanoparticles with truncated triangular and polyhedral morphologies, as well as the characteristic absorption bands of collagen, silver, and carboxymethylcellulose. In vitro tests also assessed the stability, functionality, and the degradability rate of the obtained wound-dressings. Antimicrobial assay performed on Gram-negative (Escherichia coli), Gram-positive (Staphyloccocus aureus) bacteria, and yeast (Candida albicans) models demonstrated that composite wound dressings based on collagen, carboxymethylcellulose, and AgNPs are suitable for skin lesions because they prevent the risk of infection and have prospective wound healing capacity. Moreover, the cell toxicity studies proved that the obtained materials can be used in long time treatments, with no cytotoxic effects.

Fish collagen is the safest source of collagen at present, the extraction being performed on secondary sources as skin, bones, scales or fins resulted after fish processing. The aim of the present study was to obtain biocompatible collagen hydrolysates from waste Cyprinus carpio skin, the main aquaculture species in Romania using an inexpensive and “green” neutral hydrolysis process. Neutral hydrolysis of pretreated fish skins performed for 6 hours at a temperature of 135°C and a pressure of 315 kPa produced collagen hydrolysates in 24.6-35.5% yields depending on the adopted pretreatment procedure. The extensive characterization of hydrolysate samples revealed a high purity degree (98% protein content, undetected ash content, pH value in the range 6-7), also confirmed by the absence of undesired aggregates in the characteristic fibril structure as determined by electronic microscopy. A specific collagen hydrolysate random coil structure and the absence of triple helix was determined by FTIR analysis and sustained by CD spectroscopy and X-ray diffraction. The biocompatibility assessment for the obtained fish collagen hydrolysates revealed no cytotoxic effect on Human keratinocytes, with an 80% cell viability, superior as compared to conventional bovine collagen hydrolysate.Neutral hydrolysis of waste Cyprinus carpio skin yielded collagen hydrolysates with determined characteristics and biocompatibility superior to bovine collagen, suitable for application in foods, cosmetics and pharmaceutical industry.

Cartilage damage is difficult to self-heal due to an avascular microenvironment and distinct mechanical properties. These features are a challenge in designing a cartilaginous tissue with repairing effect without producing any local infections. Thus, a biodegradable scaffold in which the drug can be incorporated is preferable. Drug delivery systems based on collagen sponges have progressively become remarkable biomaterials for different medical applications. The aim of this work was to design and characterize some collagen/chondroitin sulfate supports with doxycycline for cartilage tissue regeneration. The doxycycline should prevent the development of potential infections. Collagen, chondroitin sulfate and doxycycline gels were cross-linked with different concentrations of glutaraldehyde and then freeze-dried in order to obtain collagen matrices. The structural characteristics for the new synthesized biomaterials were firstly assessed by infrared spectroscopy (FT-IR), and scaffolds morphology was then evaluated by optical microscopy and water uptake. The enzymatic biodegradation was also performed. Also, the sponges surface properties were quantified through contact angle. The in vitro doxycycline kinetics release was performed with a dissolution equipment and the release mechanism was investigated. The obtained results recommend these new scaffolds based on doxycycline/collagen/chondroitin sulfate as a promising approach for the treatment of cartilage problems.

The goal of this work was to formulate and characterize some O/W emulsions, designed as skin anti-aging creams. The cosmetic formulations based on collagen hydrolysate, caffeine and natural ingredients (essential and vegetable oils) were evaluated organoleptically, in terms of pH, morphological, superficial and rheological properties. The rheological measurements were carried out at 23 and 32°C, and the shear stress versus shear rate ascending and descending rheograms were built, as well as the flow patterns viscosity versus shear rate. All emulsions obtained are stable at different temperatures and the pH values correspond to the skin physiological one, indicating that cosmeceuticals can be safely applied to the skin. Results from the optical microscopy analysis show that all emulsions presented a creamy and foamy appearance. The superficial profiles, quantified through contact angle at solid/liquid interface, indicated a high emulsions hydrophilicity degree. The emulsions showed a pseudoplastic and thixotropic behaviour, facilitating the flow formulations and the topical application. The flow properties were quantified according to the Power law model, and the thixotropic analysis was performed using specific descriptors as thixotropic area and thixotropic index. The designed emulsions presented physico-chemical properties adequate for cosmetic skin care product formulations.

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.

We report in this paper the synthesis and characterization of a new collagen-based material. This material was obtained in a spongy form and was functionalized with an antibiotic, ciprofloxacin. The targeted applications of these kind of materials concern the post-operative prophylaxis. The in vitro tests (antimicrobial, cytotoxic, drug release) showed that sponges with a concentration of 0.75 g of ciprofloxacin per gram of collagen could be beneficial for the desired applications.

Myrtus communis L. is one of the important aromatic and medicinal species from the Mediterranean area. It is used in various fields such as culinary, cosmetic, pharmaceutical, therapeutic, and industrial applications. Thus, a Box&ndash, Wilson experimental plan was used in this study to select the optimal operating conditions in order to obtain high volumes of essential oils. The factorial design method was applied to evaluate at an industrial scale the effect of major process variables on the essential oil extraction from Myrtus communis L. herbs by the steam distillation method. The input variables considered as significant operating conditions were: X1&mdash, boiler occupancy rate (boilers were filled to 50%, 75%, and 100%), X2&mdash, distillation duration (distillation was continued 60, 75, and 90 min), and X3&mdash, particle size (herbs were cut in sizes of 10, 20, and 30 mm via guillotine). The dependent variable selected, coded as Y, was the essential oil volume obtained (mL). The steps of the classical statistical experimental design technique were complemented with the Taguchi method to improve the extraction efficacy of essential oil from Myrtus communis L., and the optimum parameter conditions were selected: boiler occupancy rate 100%, distillation duration 75 min, and particle size 20 mm. Following the optimum parameters, the GC-MS assay revealed for the Myrtus communis L. essential oil two predominant components, &alpha, pinene&mdash, 33.14% and eucalyptol&mdash, 55.09%.

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.

It is well known that periodontitis causes rapid destruction of gingival and bone tissues. Topical treatments are suitable because the drug can be delivered in a proper and controlled concentration. Metronidazole proved to be efficient for patients with aggressive periodontitis. By this study we aimed to obtain spongious drug delivery systems for local periodontitis treatment based on collagen, strontium renalate and metronidazole. Collagen spongious forms were obtained by lyophilisation of composite gels based on collagen:strontium ranelate (50:50) and different concentrations of metronidazole. The obtained spongious forms were characterized by FT-IR, water up-take, optic microscopy and in vitro release of metronidazole. The prepared matrices absorbed a maximum amount of water after 30 min. The most absorbent sample is the reference one (only collagen) which absorbed about 35% water; the adding of metronidazole decrease the water absorption due to its lipophilic behavior. The samples with strontium are more compact and they absorbed less water than the ones without strontium. Because the samples were not cross-linked they degrade during 24 hours of water absorption process. The drug percentage released was influenced by the drug and strontium ranelate concentrations. The analysis performed sponges indicate that these composites can be useful as drug delivery supports.

Fire and burns represent the fourth cause of death in the world. Numerous options for dressings exist, but their selection should be based on several factors such as burn severity, wound location and water retention. Collagen (COLL) is the most common protein in the human body and, due to its biocompatibility, is the main component in biomaterials development. Mefenamic acid (MA) is a non-steroidal anti-inflammatory drug with analgesic properties, and carboxymethylcellulose (NaCMC) is a biocompatible and biodegradable polymer that is commonly used in biomedical field. Collagen - carboxymethylcellulose - mefenamic acid hydrogels, developed in order to be used in burn treatments were lyophilized and the corresponding spongious matrices were investigated by optical microscopy, FT-IR spectroscopy, water absorption, enzymatic degradation and drug release kinetics studies. All tests revealed proper morphological structure, favourable release patterns, convenient swelling capacity and degradation profiles, indicating the possibility of their use for medical applications.

The pain management is therefore of paramount importance and the local anesthetic treatment has to be considered. Thus, the purpose of this study was to design and characterize some collagen microcapsules incorporating an anesthetic. The collagen hydrolysate was prepared by spray-drying forming micro sizes spheres (microcapsules) which were loaded with 1% lidocaine (anesthetic) and cross-linked with different cross-linking agent: tannic acid, glutaraldehyde and genipin, in order to obtain solution for tooth pain. The wetting behavior of dried microcapsules powders was determined by contact angle measurement. The microcapsule solutions were characterized by dynamic light scattering (DLS) and in vitro release of lidocaine was investigated. These therapeutically products, based on collagen microcapsules, a local anesthetic and three cross-linking agents, could have potential biomedical application in tooth pain healing treatment.

The aim of this study is to design, develop and evaluate new biohybrid sponges based on polymers (collagen and polyvinyl alcohol) with and without indomethacin as anti-inflammatory drug model to be used for tissue regeneration in wound healing. Type I fibrillar collagen in the form of a gel and different concentrations of polyvinyl alcohol were mixed together to prepare composite gels. Both control samples, without indomethacin and with indomethacin, were obtained. All samples were crosslinked with glutaraldehyde. By freeze-drying of hydrogels, the spongious forms (matrices) were obtained. The matrices were characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), water absorption, enzymatic degradation and in vitro indomethacin release. The pharmacological effect of the spongious biohybrid matrices was determined on an experimental model of burns induced to Wistar rats. The SEM images showed a porous structure with interconnected pores. Collagen sponges present a structure with pore sizes between 20 and 200 &micro, m, which became more and more compact with polyvinyl alcohol addition. The FT-IR showed interactions between collagen and polyvinyl alcohol. The enzymatic degradation indicated that the most stable matrix is the one with the ratio 75:25 of collagen:polyvinyl alcohol (ACI75), the other ones being degradable in time. The kinetic data of indomethacin release from matrices were fitted with different kinetic models and highlighted a biphasic release of the drug. Such kinetic profiles are targeted in skin wound healing for which important aspects are impaired inflammation and local pain. The treatment with sponges associated with anti-inflammatory drug had beneficial effects on the healing process in experimentally induced burns compared to the corresponding matrices without indomethacin and the classical treated control group.

Many research studies are directed toward developing safe and efficient collagen-based biomaterials as carriers for drug delivery systems. This article presents a comparative study of the properties of new collagen sponges prepared and characterized by different methods intended for biomedical applications. The structural integrity is one of the main properties for a biomaterial in order for it to be easily removed from the treated area. Thus, the effect of combining a natural polymer such as collagen with an antimicrobial drug such as oxytetracycline or doxycycline and glutaraldehyde as the chemical cross-linking agent influences the cross-linking degree of the material, which is in direct relation to its resistance to collagenase digestion, the drug kinetic release profile, and in vitro biocompatibility. The enzymatic degradation results identified oxytetracycline as the best inhibitor of collagenase when the collagen sponge was cross-linked with 0.5% glutaraldehyde. The drug release kinetics revealed an extended release of the antibiotic for oxytetracycline-loaded collagen sponges compared with doxycycline-loaded collagen sponges. Considering the behavior of differently prepared sponges, the collagen sponge with oxytetracycline and 0.5% glutaraldehyde could represent a viable polymeric support for the prevention/treatment of infections at the application site, favoring tissue regeneration.

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.