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Background Low-level laser therapy (LLLT) has been clinically accepted to accelerate the nerve regeneration process after a nerve injury or transection. We aimed to investigate the neuronal basis and the influence of LLLT on brain functional networks in traumatic patients with olfactory dysfunction.Methods Twenty-four Patients with traumatic anosmia/hyposmia were exposed to pleasant olfactory stimuli during a block-designed fMRI session. After a 10-week period, patients as control group and patients who had completed the sessions of LLLT were invited for follow-up testing using the same fMRI protocol. Two-sample t-tests were conducted to explore group differences in activation responding to odorants (p-FDR-corrected <0.05). Differences of functional connectivity were compared between the two groups and the topological features of the olfactory network were calculated. Correlation analysis was performed between graph parameters and TDI score.Results Compared to controls, laser-treated patients showed increased activation in the cingulate, rectus gyrus, and some parts of the frontal gyrus. Shorter pathlength (p= 0.047) and increased local efficiency (p= 0.043) within the olfactory network, as well as decreased inter-network connectivity within the whole brain were observed in patients after laser surgery. Moreover, higher clustering and local efficiency were related to higher TDI score, as manifested in increased sensitivity to identify odors.Conclusions The results support that low-level laser induces neural reorganization process and make new connections in the olfactory structures. Furthermore, the connectivity parameters may serve as potential biomarkers for traumatic anosmia or hyposmia by revealing the underlying neural mechanisms of LLLT.

The tympanic membrane (TM) integrity is necessary for our normal hearing function. TM perforations pose significant morbidities such as middle ear infection, recurrent otorrhea, hearing loss, and acquired cholesteatoma. Myringoplasty is commonly performed to repair chronic perforations; although various grafts and materials have been utilized to promote TM regeneration, all have associated restrictions. This study aimed to prepare and evaluate the efficacy and feasibility of a tissue-engineered patch based on silk fibroin and gelatin (SF-GT) to improve regeneration. A casting technique was used to make the SF-GT films, using 0–30 v/v% GT, as it is shown that films are remarkably efficient for TM regeneration, easy to mass produce and cheap to make. The surface morphology (SEM), chemical structure (FTIR), crystallinity (XRD), mechanical strength (tensile test), water uptake and in vitrodegradation, and cellular biocompatibility (MTT and scratch) were investigated for SF-GT films, and the optimal patch was chosen based on the results (SF-30GT). SF-30GT was used for in vivostudies in a rat model with TM perforations to induce TM regeneration. The morphology of the TM was assessed at days 0, 3, 5, 7, 9 and 11 post-implantation using otoscopy and functional outcomes by auditory brainstem responses (ABRs). This study indicates that compared with the control group (spontaneous healing), the SF-30GT scaffold was more effective in promoting early TM regeneration (complete healing at day 7) and normal hearing (back to 20 dB after healing), suggesting that this scaffold can be a potential substitute for clinical use.

The nasal septal cartilage plays an important role in the growth of midface and as a vertical strut preventing the collapse of the nasal bones. The repair of nasal cartilage defects remains a major challenge in reconstructive surgery. The tissue engineering strategy in the development of tissue has opened a new perspective to generate functional tissue for transplantation. Given the poor regenerative properties of cartilage and a limited amount of autologous cartilage availability, intense interest has evoked for tissue engineering approaches for cartilage development to provide better outcomes for patients who require nasal septal reconstruction. Despite numerous attempts to substitute the shapely hyaline cartilage in the nasal cartilages, many significant challenges remained unanswered. The aim of this research was to carry out a critical review of the literature on research work carried out on the development of septal cartilage using a tissue engineering approach, concerning different cell sources, scaffolds and growth factors, as well as its clinical pathway and trials have already been carried out.