Penetration of topically applied polymeric nanoparticles across the epidermis of thick skin from rat.

The barrier function of the epidermis poses a significant challenge to nanoparticle-mediated topical delivery. A key factor in this barrier function is the thickness of the stratum corneum (SC) layer within the epidermis, which varies across different anatomical sites. The epidermis from the palms and soles, for instance, have thicker SC compared to those from other areas. Previous studies have attempted to bypass the SC layer for nanoparticle penetration by using physical disruption; however, these studies have mostly focused on non-thick skin. In this study, we investigate the role of SC-disrupting mechano-physical strategies (tape-stripping and microneedle abrasion) on thick and thin skin, in allowing transdermal penetration of topically applied nanoparticles using an ex-vivo skin model from rat. Our findings show that tape-stripping reduced the overall thickness of SC in thick skin by 87%, from 67.4 ± 17.3µm to 8.2 ± 8.5µm, whereas it reduced thin skin SC by only 38%, from 9.9 ± 0.6µm to 6.2 ± 3.2µm. Compared to non-thick skin, SC disruption in thick skin resulted in higher nanoparticle diffusion. Tape-stripping effectively reduces SC thickness of thick skin and can be potentially utilized for enhanced penetration of topically applied nanoparticles in skin conditions that affect thick skin.

A Footprint-Like Intracranial Solitary Fibrous Tumor/Hemangiopericytoma With Extracranial Extension and Acute Intratumoral Hemorrhage.

BACKGROUND: Intracranial solitary fibrous tumors/hemangiopericytomas (ISFTs/HPCs) are extremely rare spindle-cell tumors that are mostly benign and derived from mesenchymal tissue. Extracranial metastasis and intratumoral hemorrhage are considered to be special manifestations of malignant tumors, of which extracranial metastases of ISFTs/HPCs have been reported, while tumor hemorrhage has rarely been described. Here, the authors present an interesting case of ISFTs/HPCs with acute intratumoral hemorrhage. CLINICAL PRESENTATION: A 72-year-old woman underwent brain magnetic resonance imaging (MRI) for recurrent headaches and nausea. The MRI scan showed a footprint-like space-occupying lesion in the bilateral parietooccipital lobe. This lesion had multiple cystic components and invaded the superior sagittal sinus, destroying adjacent cranial bones. While waiting for routine surgery, the patient suddenly developed acute tumor bleeding and then underwent emergency surgery. Postoperatively, the diagnosis of ISFT/HPC was confirmed by pathological and immunohistochemical analysis. DISCUSSIONS AND CONCLUSIONS: The diagnosis of ISFT/HPC mainly depends on pathological and immunohistochemical results. Malignant cases with cystic necrosis may be prone to acute hemorrhage. Early total surgical excision can provide a good clinical prognosis. Adjuvant radiotherapy is an effective supplement to surgical treatment. Metastasis and recurrence require long-term follow-up monitoring.