Chitosan: A Good Candidate for Sustained Release Ocular Drug Delivery Systems

This chapter focuses on the eye, one of the most important organs of humans. Current data on pathophysiology of the human eye are presented in direct correlation with a range of therapeutic products, with a well-known and widely used material, namely chitosan. Applications of chitosan biopolymer are described in the development of innovative, modern, therapeutic devices and solutions. Thus, chitosan is a good excipient either for classic drop-type ocular systems, as well as for complex drug systems such as nanostructures (nanoparticles, nanomicelles and nanosuspensions), liposomes, microemulsions, microspheres, in situ hydrogels and inserts or implants. A number of disadvantages for ocular administration of the drugs are thus overcome

Natural and Artificial Superwettable Surfaces-Superficial Phenomena: An Extreme Wettability Scenario

With the help of biomimetics, superficial characteristics were transposed, through various methods, onto artificially obtained materials. Many industrial fields applied surface architecture modifications as improvements of classic materials/methods. The medico-pharmaceutical, biochemical, transportation, and textile fields are few examples of industrial areas welcoming a “structural change.” Anti-bioadhesion was widely exploited by means of antibacterial or self-cleaning fabrics and cell culturing/screening/isolation. Anti-icing, antireflective, and anticorrosion materials/coatings gained attention in the transportation and optical device fields. Interdisciplinary approaches on extreme wettability include “solid-fluid” formations called liquid marbles, which will be further discussed as a superhydrophobic behavior exponent

DERMATOCOSMETICS FACIAL MASKS FOR TOPICAL TREATMENT OF ACNE

Acne is one of the most common skin diseases affecting mostly adolescents, but can occur also into adulthood. Acne can have profound psychological and social effects, not only for high severity acne, but even in less severe cases. Staphylococcus epidermidis (S. epidermidis) bacteria and Propionibacterium acnes (P. acnes) bacteria are considered to cause this disease. Over time they have used many treatments for acne especially antibiotics, metronidazole showing positive effects and long-lasting. Thus, the purpose of this study was to design and investigate some facial masks in form of membranes with collagen and metronidazole to reduce and prevent adverse effects of conventional treatments using for acne. Type I fibrillar collagen gel was the main component of all masks. Hydrogels based on collagen, metronidazole, starch and polyvinilpyrolidone showed a pseudoplastic behavior with yield stress facilitating their flow and allowing their good manipulation. The membranes were obtained by drying the hydrogels in controlled environment and characterized by water absorbtion and enzymatic degradation. The results relieves that the presence of polymers (starch and polyvinylpirolidone) influence the stability and integrity of the membranes obtain. Based on these results, we could conclude that the obtained masks are potentially usable as a favorable solution in acne disease

Innovative Biomaterials Based on Collagen-Hydroxyapatite and Doxycycline for Bone 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. The in vitro release 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

Promising Hydrogels-Based Dressings for Optimal Treatment of Cutaneous Lesions

Worldwide, cutaneous lesions care represents a daily challenge for the medical system, with an increasing prevalence from year to year (from ~5 million in 2005 to about 8 million in 2018) and high costs for their treatment (between ~$28 billion and ~$97 billion). Injuries are the most frequent and destructive form of skin damage, affecting patients’ quality of life. To promote wound healing, an ideal treatment involves proper dressings that can manage the local pain, inflammation, or infection. Passive or dry traditional dressings, such as cotton, gauze, or lint, have limited therapeutic actions and demand periodic replacement of the dressing. Therefore, an optimal alternative for advanced wound care is represented by hydrogels, one of the five classes of modern dressings, which assure excellent local moisture, due to their high ability to absorb a large volume of water inside their three-dimensional networks. Moreover, hydrogels possess suitable biocompatibility, biodegradability, porosity, elasticity, flexibility, and biological properties similar to the extracellular matrix. This chapter presents the main characteristics of the hydrogels and the recent research regarding the development of new hydrogel dressings, based on natural, semi-synthetic, or synthetic biopolymers, loaded with varied therapeutic agents to stimulate the tissue regeneration of different etiologies cutaneous lesions

Hydrogels - Smart Materials for Biomedical Applications

Hydrogels, as three-dimensional polymer networks, are able to retain a large amount of water in their swollen state. The biomedical application of hydrogels was initially hampered by the toxicity of cross-linking agents and the limitations of hydrogel formation under physiological conditions. However, emerging knowledge in polymer chemistry and an increased understanding of biological processes have resulted in the design of versatile materials and minimally invasive therapies.The novel but challenging properties of hydrogels are attracting the attention of researchers in the biological, medical, and pharmaceutical fields. In the last few years, new methods have been developed for the preparation of hydrophilic polymers and hydrogels, which may be used in future biomedical and drug delivery applications. Such efforts include the synthesis of self-organized nanostructures based on triblock copolymers with applications in controlled drug delivery. These hydrogels could be used as carriers for drug delivery when combined with the techniques of drug imprinting and subsequent release. Engineered protein hydrogels have many potential advantages. They are excellent biomaterials and biodegradables. Furthermore, they could encapsulate drugs and be used in injectable forms to replace surgery, to repair damaged cartilage, in regenerative medicine, or in tissue engineering. Also, they have potential applications in gene therapy, although this field is relatively new