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.

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.

In this paper, Bombyx mori silk sericin nanocarriers with a very low size range were obtained by nanoprecipitation. Sericin nanoparticles were loaded with doxorubicin, and they were considered a promising tool for breast cancer therapy. The chemistry, structure, morphology, and size distribution of nanocarriers were investigated by Fourier transformed infrared spectroscopy (FTIR–ATR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and dynamic light scattering (DLS). Morphological investigation and DLS showed the formation of sericin nanoparticles in the 25–40 nm range. FTIR chemical characterization showed specific interactions of protein–doxorubicin–enzymes with a high influence on the drug delivery process and release behavior. The biological investigation via breast cancer cell line revealed a high activity of nanocarriers in cancer cells by inducing significant DNA damage.

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.

Collagen is one of the most used biomaterials for bone defects repair, proving good results in tissue reconstruction research, and also its features recommend it as a very attractive drug delivery scaffold for local treatment of the affected osseous tissue. The inflammatory response is a common reaction that occurs in bone disease, the topical administration of anti-inflammatory drugs (NSAIDs) representing a reliable strategy to overcome this issue. The purpose of this paper was the physical-chemical and biopharmaceutical evaluation of some spongious matrices consisting of collagen as release support and niflumic acid as drug NSAID model, usable in bone tissue regeneration. Type I fibrillar collagen gel (2.4% 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 sponges were obtained by freeze-drying of gels adjusted at 1% and 7.3 pH, with different dextran (0; 10 and 20%) and MgO (0; 30 and 60%) concentrations (reported to dry collagen), with 0.5% and without niflumic acid (NA) (reported to gel) and the same amount of glutaraldehyde (0.5% reported to collagen dry substance). The sponges were evaluated through water absorption, FT-IR spectroscopy and optical microscopy. In vitro NA release from the designed sponges was carried out using a sandwich device adapted to a dissolution equipment. Power law kinetic model was applied to explain drug release from the tested formulations. The NA release from collagen sponges showed a non-Fickian transport mechanism. The addition in different concentrations of dextran and MgO leads to more compact structures and improves stability of collagenic matrices. Our results showed that the designed support could be adequate for treating the inflammation associated with a bone defect in orthopedic surgery.