During recent decades, researchers all around the world have focused on the characteristic pros and cons of the different drug delivery systems for cornea tissue change for sense organs. The delivery of various drugs for cornea tissue is one of the most attractive and challenging activities for researchers in biomaterials, pharmacology, and ophthalmology. This method is so important for cornea wound healing because of the controllable release rate and enhancement in drug bioavailability. It should be noted that the delivery of various kinds of drugs into the different parts of the eye, especially the cornea, is so difficult because of the unique anatomy and various barriers in the eye. Nanoparticles are investigated to improve drug delivery systems for corneal disease. Biodegradable nanocarriers for repeated corneal drug delivery is one of the most attractive and challenging methods for corneal drug delivery because they have shown acceptable ability for this purpose. On the other hand, by using these kinds of nanoparticles, a drug could reside in various part of the cornea for longer. In this review, we summarized all approaches for corneal drug delivery with emphasis on the biodegradable nanoparticles, such as liposomes, dendrimers, polymeric nanoparticles, niosomes, microemulsions, nanosuspensions, and hydrogels. Moreover, we discuss the anatomy of the cornea at first and gene therapy at the end.
1 February 2013 in Clinical Orthopaedics and Related Research
The ability to apply casts and splints is a technical skill that requires practice and understanding of basic principles of musculoskeletal medicine. A video in which a given procedure is simulated on a dummy can represent reality under controlled conditions. A decrease in physician competency in musculoskeletal medicine is the result of educational deficiencies at the medical school level. We asked whether (1) a supplemental video educational program enhances performance of medical students’ musculoskeletal clinical skills and (2) factors such as the proportion of orthopaedic professors to students, sex, age, and previous scores of medical students affected the clinical skills of medical students. We allocated 474 medical students into one of two groups: all participants received 90 minutes of lecture instruction on how to splint and cast but one group viewed the supplemental instructional video and the other did not. There were no differences in terms of sex, age, basic science exam scores, or grade point average of the groups. Thirteen specific skills in splinting an injured limb were evaluated. We recorded grade point averages. We developed a 10-point scoring system and graded each student on their splinting skills 6 months after the lectures. The medical students who watched the video had an average score of 7.6, whereas the control group’s average score was 2.0. We observed a positive association between watching the educational video and clinical exam score. A higher professor-to-student ratio was associated with lower student Objective Structured Clinical Examination score. Our observations suggest a supplemental video instructional program improved the performance of musculoskeletal clinical skills in comparison to only a traditional lecture series.
Corneal disease is one of the most significant causes of blindness around the world. Presently, corneal transplantation is the only way to treat cornea blindness. It should be noted that the amount of cornea that people donate is so much less than that required (1:70). Therefore, scientists have tried to resolve this problem with tissue engineering and regenerative medicine. Fabricating cornea with traditional methods is difficult due to their unique properties, such as transparency and geometry. Bioprinting is a technology based on additive manufacturing that can use different biomaterials as bioink for tissue engineering, and the emergence of 3D bioprinting presents a clear possibility to overcome this problem. This new technology requires special materials for printing scaffolds with acceptable biocompatibility. Hydrogels have received significant attention in the past 50 years, and they have been distinguished from other materials because of their unique and outstanding properties. Therefore, hydrogels could be a good bioink for the bioprinting of different scaffolds for corneal tissue engineering. In this review, we discuss the use of different types of hydrogel for bioink for corneal tissue engineering and various methods that have been used for bioprinting. Furthermore, the properties of hydrogels and different types of hydrogels are described.
Background: Reconstructions of forearm fracture nonunions are frequently complex. A few studies that help guide the treatment of forearm nonunion have been reported. We offer a novel surgical technique to treat nonunion of the forearm using a regional vascularized bone graft. Methods: Four females and 5 males ranging from 27 to 74 years of age with 7 ulna and 2 radius nonunions were surgically treated by pedicle grafting with a posterior interosseous bone flap (PIBF) and internal fixation with a plate. There were no cases with extensive soft tissue damage or infection. Pre- and postoperatively (mean 21 months), all patients were assessed by radiographs and for function by the Disabilities of the Arm, Shoulder and Hand (DASH) score. Results: Function of the upper extremity was improved in all patients. DASH scores improved from 61.2 points pre-operatively to 12 points at final follow-up. All nonunions were united uneventfully. Conclusions: Following debridement of the necrotic tissue, the bone defect can be filled with a vascularized graft from posterior interosseous pedicles. Pedicled PIBF is a safe and useful novel technique in cases of atrophic or hypertrophic nonunion of the middle third of the radius or proximal two-thirds of the ulna.