Induced pluripotency in the context of stem cell expansion bioprocess development, optimization, and manufacturing: a roadmap to the clinic.

The translation of laboratory-scale bioprocess protocols and technologies to industrial scales and the application of human induced pluripotent stem cell (hiPSC) derivatives in clinical trials globally presents optimism for the future of stem-cell products to impact healthcare. However, while many promising therapeutic approaches are being tested in pre-clinical studies, hiPSC-derived products currently account for a small fraction of active clinical trials. The complexity and volatility of hiPSCs present several bioprocessing challenges, where the goal is to generate a sufficiently large, high-quality, homogeneous population for downstream differentiation-the derivatives of which must retain functional efficacy and meet regulatory safety criteria in application.

Optimized serial expansion of human induced pluripotent stem cells using low-density inoculation to generate clinically relevant quantities in vertical-wheel bioreactors.

Human induced pluripotent stem cells (hiPSCs) have generated a great deal of attention owing to their capacity for self-renewal and differentiation into the three germ layers of the body. Their discovery has facilitated a new era in biomedicine for understanding human development, drug screening, disease modeling, and cell therapy while reducing ethical issues and risks of immune rejection associated with traditional embryonic stem cells. Bioreactor-based processes have been the method of choice for the efficient expansion and differentiation of stem cells in controlled environments.

Changes in Vitreoretinal Adhesion With Age and Region in Human and Sheep Eyes.

While several studies have qualitatively investigated age- and region-dependent adhesion between the vitreous and retina, no studies have directly measured the vitreoretinal strength of adhesion. In this study, we developed a rotational peel device and associated methodology to measure the maximum and steady-state peel forces between the vitreous and the retina. Vitreoretinal adhesion in the equator and posterior pole were measured in human eyes from donors ranging 30 to 79 years of age, and in sheep eyes from premature, neonatal, young lamb, and young adult sheep.

Coefficient of Friction Between Carboxymethylated Hyaluronic Acid-Based Polymer Films and the Ocular Surface.

Purpose: Hyaluronic acid-based polymer films are emerging as drug-delivery vehicles for local and continuous drug administration to the eye. The highly lubricating hyaluronic acid increases comfort, but displaces films from the eye, reducing drug exposure and efficacy. Previous studies have shown that careful control of the surface interaction of the film with the eye is critical for improved retention.

Finite Element Design Optimization of a Hyaluronic Acid-Based Hydrogel Drug Delivery Device for Improved Retention.

Drug-loaded hydrogel devices are emerging as an effective means of localized and sustained drug delivery for the treatment of corneal conditions and injuries. One such device uses a novel, thiolated crosslinked carboxymethylated, hyaluronic acid-based hydrogel (CMHA-S) film to deliver drug to the ocular surface upon placement into the inferior fornix of the eye. While proven to be very safe and effective, the CMHA-S film tends to dislodge in the highly-lubricated ocular environment, thereby reducing drug delivery efficiency and drug efficacy.

Age-related changes in dynamic moduli of ovine vitreous.

Multiple rheological studies have characterized the dynamic material properties of adult vitreous, but no studies have investigated vitreous properties in the immature eye. In this study, premature, infant and adult ovine vitreous specimens were tested in shear to identify differences in dynamic moduli with age. Significant inertial artifact and rapid degradation of the vitreous ex vivo hindered the ability to accurately collect dynamic data through standard oscillation protocols.

Otodental syndrome: a case report.

The purpose of this article is to describe the clinical features of otodental syndrome. A 9-year-old boy presented with dental abnormalities that have been described for otodental syndrome. The characteristic findings included large bulbous crowns in canine and molar teeth of both dentitions, deep vertical enamel fissures separating the cusps of affected molars, and hypoplastic yellow areas on the labial surfaces of the canines.

Angiographic correlates of "spotty" coronary artery calcium detected by electron-beam computed tomography in patients with normal or near-normal coronary angiograms.

To characterize relations between coronary plaque formation, focal, "spotty" coronary calcified lesions, and luminal narrowing, coronary calcium was examined by electron-beam computed tomography in 49 patients with normal or near-normal angiograms. Based on a coronary segmental analysis and on a patient-by-patient analysis, spotty coronary calcium was associated with slight angiographic changes consistent with early atherosclerotic disease and compensatory arterial remodeling.

Transformation of hamster embryo cells by chymotrypsin-treated and untreated polyoma virus: characterization of transformants.

The ability of chymotrypsin-treated (chymo+) and untreated (chymo-) polyoma virus to transform cultured hamster embryo fibroblasts was examined. The data show that exposure to this protease reduces the ability of the virus to transform non-permissive cells to essentially the same extent as it reduces its ability to replicate in permissive cells. Twenty-five lines of transformed cells were established from colonies growing in soft agar, and after 20 in vitro passages, cells of all lines were characterized with respect to their ability to form colonies in soft agar and their tumorigenicity in hamsters.

Rescue of BKV from BKV-transformed hamster, rat, and mouse cells: correlation with levels of nonintegrated viral DNA.

Infectious BKV was rescued from 39 of 40 lines of virus-free, BKV-transformed hamster, rat, and mouse cells, which had been either maintained continuously in culture or reestablished in culture after one or more passage in the appropriate host, by Sendai virus-catalyzed fusion with permissive cells. Striking differences were observed among the 39 lines with respect to the efficiency of virus rescue. Fourteen of the lines were examined for the presence of nonintegrated viral DNA by dot-blot hybridization.

Evidence that polyoma polypeptide VP1 is a serine protease.

It has been shown that when purified polyoma (Py) virions are dissociated by incubation in 150 mM NaCl-50 mM Tris-HCl (pH 8.5) containing 1 mM EGTA and 3 mM DTT, two new polypeptides (MW 43.5K and 40K) are produced by proteolysis of virion polypeptide VP1.

Studies of two temperature-sensitive mutants of Mengo virus.

Studies of the synthesis of viral ribonucleates and polypeptides in cells infected with two RNA- ts mutants of Mengo virus (ts 135 and ts 520) have shown that when ts 135 infected cells are shifted from the permissive (33 degrees C) to the nonpermissive (39 degrees C) temperature: (i) the synthesis of all three species of viral RNA (single stranded, replicative form, and replicative intermediate) is inhibited to about the same extent, and (ii) the posttranslational cleavage of structural polypeptide precursors A and B is partially blocked. Investigations of the in vivo and in vitro stability of the viral RNA replicase suggest that the RNA- phentotype reflects a temperature-sensitive defect in the enzyme. The second defect does not appear to result from the inhibition of viral RNA synthesis at 39 degrees C, since normal cleavage of polypeptides A and B occurs in wt Mengo-infected cells in which viral RNA synthesis is blocked by cordycepin, and at the nonpermissive temperature in ts 520 infected cells.

Isolation and characterization of BK virus-transformed rat and mouse cells.

The isolation and characterization of four groups of BK virus (BKV)-transformed rat embryo fibroblast (RE) and mouse kidney (MK) cells are described. They consist of (1) seven RE lines transformed with a BKV pool containing a high proportion of defective virions, and (2) 16 RE, (3) 14 Balb/c-MK and (4) 2 Swiss ICR-MK lines, all transformed, at different input multiplicities, with a pool of BKV free of defective virions. None of the lines produces BKV, all contain BKV T antigen and all grow to higher saturation densities and have higher plating efficiencies than do the corresponding control cells.

Observations on the growth and plaque assay of BK virus in cultured human and monkey cells.

Although human embryo kidney (HEK), muscle (HEM) and lung (HEL) cells are capable of supporting the replication of BK virus (BKV) through passage levels 9, 12 and 12 respectively, only third, fourth and fifth passage level HEK cells were found to be satisfactory for the plaque assay of the virus. BSC-I and VERO cells can also be used for the plaque assay of BKV. However, in HEK cells plaques can be visualized in 20 days (compared to 28 days in BSC-I cells), and since in VERO cells the plaques are poorly defined and the titre about I log10 lower than in either HEK or BSC-I cells, HEK cells were the ones chosen for use.