Can Cross-Linked Siliconized PFS Come to the Rescue of the Biologics Drug Product?

Silicone can present a challenge during the development of a biologics drug product particularly in pre-filled syringe (PFS). Due to silicone related challenges, substantial changes in components and manufacturing of the PFS are being sought. Cross-linking of the silicone being one of them, can help reduce mobilization of the silicone into drug product whilst retaining its functionality of lubrication during injection. In this work, we systematically compare the stability of a fusion protein and monoclonal antibody formulation in conventionally siliconized and cross-linked siliconized PFS available from commercial manufacturers. The two types of syringes did not influence the aggregation profile of proteins as determined by HP-SEC. Compared to conventionally siliconized PFS, a cross-linked siliconized PFS can have a favorable or indifferent impact (depending on vendor) on the sub-visible particles profile as assessed by light obscuration and microflow imaging. The different PFS after 24 months of long-term storage showed comparable functionality attributes like break-loose/gliding force and silicone oil distribution. Cross-linked siliconized PFS can offer an incremental advantage over conventionally siliconized PFS for the moderately concentrated protein solutions, however the differences in the quality of these PFS amongst manufacturers is an important aspect that needs to be considered as shown in this study.

Keratinocyte-specific deletion of the receptor RAGE modulates the kinetics of skin inflammation in vivo.

The receptor for advanced glycation end products (RAGE) is a pattern recognition receptor causally related to the pathogenesis of acute and chronic inflammation. In a mouse model of inflammation-driven skin carcinogenesis, RAGE deletion conferred protection from the development of skin tumors due to a severely impaired cutaneous inflammation. Although the impact of RAGE expression in immune cells was shown to be essential for the maintenance of a cutaneous inflammatory reaction, the role of RAGE in keratinocytes remained unsolved. Using mice harboring a keratinocyte-specific deletion of RAGE, we analyzed its role in the regulation of an acute inflammatory response that was induced by topical treatment of the back skin with the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA). We show that RAGE expression in cutaneous keratinocytes modulates the strength and kinetics of acute inflammation and supports the maintenance of epidermal keratinocyte activation. To address the underlying molecular mechanism, we isolated interfollicular epidermis by laser microdissection for gene expression analysis, and identified RAGE as a regulator in the temporal control of TPA-induced epidermal tumor necrosis factor alpha transcript levels. In summary, our data demonstrate that RAGE expression in keratinocytes is critically involved in the perpetuation of acute inflammation and support the central role of RAGE in paracrine communication between keratinocytes and stromal immune cells.