Epidermal growth factor stimulates fluid transport in SV40 transformed rabbit lacrimal gland cells

Impact of fluorescent probes on albumin sorption profiles to ophthalmic biomaterials

Bovine serum albumin (BSA) was conjugated to three organic fluorescent probes, 5-(4,6-dichloro-s-triazin-2-ylamino)fluorescein hydrochloride (DTAF), Rhodamine B isothiocyanate (RITC), and Lucifer yellow VS (LY). The protein sorption profile to one pHEMA-based (etafilcon A) and three silicone hydrogel (SH) contact lens types (lotrafilcon B, balafilcon A and senofilcon A) was determined using confocal laser scanning microscopy. In addition, all lenses were incubated in dye solutions containing the fluorescent probe alone; and in a separate experiment BSA accumulation was quantified using radiolabeling. The different fluorescent conjugates showed similar sorption profiles for the pHEMA-based lens, but marked differences for all SH lenses. Lotrafilcon B accumulated more protein on the surface as compared to the matrix, independent of the fluorescent probe used for conjugation. Protein sorption varied for senofilcon A, with DTAF-BSA sorbing primarily to the surface region, while the other conjugates penetrated in equal amounts into the matrix. Balafilcon A exhibited smaller differences between conjugates, with LY-BSA allowing the protein to fully penetrate the matrix, while the other conjugates showed minor surface adsorption. Sorption curves of unbound dyes were often similar compared to the conjugated results. BSA profiles to pHEMA-based and silicone hydrogel lenses were highly dependent on the fluorescent probe used and none of the probes accurately reflected quantitative protein levels for the lens materials investigated.

Current status of gene delivery and gene therapy in lacrimal gland using viral vectors

Gene delivery is one of the biggest challenges in the field of gene therapy. It involves the efficient transfer of transgenes into somatic cells for therapeutic purposes. A few major drawbacks in gene delivery include inefficient gene transfer and lack of sustained transgene expression. However, the classical method of using viral vectors for gene transfer has circumvented some of these issues. Several kinds of viruses, including retrovirus, adenovirus, adeno-associated virus, and herpes simplex virus, have been manipulated for use in gene transfer and gene therapy applications. The transfer of genetic material into lacrimal epithelial cells and tissues, both in vitro and in vivo, has been critical for the study of tear secretory mechanisms and autoimmunity of the lacrimal gland. These studies will help in the development of therapeutic interventions for autoimmune disorders such as Sjögren's syndrome and dry eye syndromes which are associated with lacrimal dysfunction. These studies are also critical for future endeavors which utilize the lacrimal gland as a reservoir for the production of therapeutic factors which can be released in tears, providing treatment for diseases of the cornea and posterior segment. This review will discuss the developments related to gene delivery and gene therapy in the lacrimal gland using several viral vector systems.