Photocrosslinked acemannan-based 3D matrices for in vitro cell culture

Current biomedical research has highlighted the potential use of medicinal plant derivatives as advanced suitable biomaterials due to their biological properties. Acemannan (ACE) is the main polysaccharide of Aloe vera (AV) leaves with many reported biological properties, including immunomodulatory activity, antibacterial action, wound healing induction, and cytocompatibility. These properties suggest that ACE is an appealing material for the development of 3D structures for biomedical purposes. In this study, ACE was modified by a methacrylation reaction using methacrylic anhydride. Further 3D sponges were developed by processing modified ACE by photocrosslinking using UV irradiation and the freeze-drying technique. Both FTIR and 1H NMR spectroscopy confirmed the effectiveness of the functionalization. SEM and m-CT revealed that the cross-sections of the methacrylated acemannan (MACE) sponges have open macropores and a narrow pore size distribution within them. We hypothesized that the intrinsic features of ACE could enhance tumor growth, mimicking the biological tumor microenvironment. Therefore, gastric cancer cells (AGS cell line) were cultured in contact with these matrices for up to 14 days to evaluate their cytocompatibility as a processed biomaterial. Results obtained by live-dead assay and MTS showed that cells are viable and metabolically active. Furthermore, confocal laser scanning microscopy analysis showed a homogeneous distribution of cells within the sponge. Therefore, the photocrosslinking on acemmann is proposed as an alternative approach that could significantly improve the processability of acemannan, allowing the production of high added-value structures enabling exploitation of its potential biomedical value.Portuguese Foundation for Science and Technology – FCT (SFRH/BPD/112140/2015, SFRH/BPD/85790/2012, respectively). This work was also financially supported by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. REGPOT-CT2012-316331-POLARIS. The authors would like to express thanks to Lorand Laboratories (Texas, USA) for the Acemannan (BiAloeÒ) suppl

Transfrontoethmoidal Approach to Medial Intraconal Lesions: Laboratory Investigation

Object. The standard superior craniotomy approach through the orbital roof is obstructed by numerous muscles, nerves, and vessels. Accessing the medial intraconal space also involves considerable brain retraction. The authors present a modified approach through the frontal sinus that overcomes these limitations. Methods. Seven fixed silicone-injected cadaveric specimens were dissected bilaterally. In addition to the superior orbital wall, the ethmoidal sinuses and medial orbital wall were removed. The anatomical relationships between the major neurovascular complexes in the medial intraconal space and the optic nerve were observed. Results. Intraconally, working space was created both in a \ superior window\ between the superior oblique and levator palpebrae muscle and in a \ medial window\ between the superior oblique and medial rectus muscle. The superior window mainly created an ipsilateral trajectory to the deep target. The medial window, which created a contralateral trajectory, provided a more inferior view of the medial intraconal space. Removal of the medial orbital wall further widened the exposure obtained from the superior window. The combination of these working windows makes the medial surface of the optic nerve available for exploration from multiple angles. Most of the major neurovascular complexes of the posterior orbit can be retracted safely without impinging on the optic nerve. Conclusions. This novel extradural transfrontoethmoidal approach affords a direct view to the medial posterior orbit without major conflicts with intraconal neurovascular structures and requires minimal brain manipulation. The approach appears to offer advantages for medially located intraconal lesions

The Challenge of Access to the Pontomesencephalic Junction: An Anatomical Study of Lateral Approach and Exposure

We quantitatively compared relative merits of lateral approaches to the pontomesencephalic junction (PMJ): anterior petrosectomy, subtemporal transtentorial, posterior petrosectomy, and retrosigmoid transtentorial. In dissected cadaveric heads, lengths of exposure were measured anteriorly from CN V along the pontomesencephalic sulcus (PMS); posterosuperiorly along the lateral mesencephalic sulcus (LMS); and posteroinferiorly along the interpeduncular sulcus (IPS). Subtemporal transtentorial approach provided best anterior exposure along the PMS (23.8 ± 4.5 mm). Posterosuperior exposures were comparable for all approaches except anterior petrosectomy (limited). Posteroinferior exposure was most with subtemporal transtentorial approach (13.2 ± 2.8 mm). CN V entry/exit point was identified through all approaches, except for subtemporal transtentorial; shortest surgical depth with posterior petrosectomy was 43.7 ± 5.5 mm. PMS-LMS-IPS convergence point: reached through all approaches, except for anterior petrosectomy (limited); shortest surgical depth with posterior petrosectomy was 40.3 ± 4.3 mm. Anterior petrosectomy provides direct anterolateral views of the pons not afforded by subtemporal approach. Subtemporal transtentorial approach provides optimal posterolateral view to the PMJ and cerebellar peduncles. Retrosigmoid transtentorial approach offers wide exposure of the lateral surface, limited on the posteroinferior PMJ by the cerebellum. The small opening of posterior petrosectomy creates an awkward corridor to anterior PMJ targets but provides a direct and shortest route to the cerebellar peduncles