Differentiation of Human Adipose-Derived Mesenchymal Stromal/Stem Cells into Insulin-Producing Cells with A Single Tet-Off Lentiviral Vector System.

OBJECTIVE: Human adipose-derived mesenchymal stromal/stem cells (hASC) constitute an attractive source of stem cells for cell-based therapies in regenerative medicine and tissue engineering as they are easy to acquire from lipoaspirate, expansion, and genetic modification ex vivo. The combination of Pdx-1, MafA, and NeuroD1 has been indicated to possess the ability to reprogram various types of cells into insulin-producing cells. The aim of this study is to investigate whether MafA and NeuroD1 would cooperate with Pdx-1 in the differentiation of hASC into insulin-producing cells. MATERIALS AND METHODS: In this experimental study, we generated polycistronic expression vectors expressing Pdx1 and MafA/NeuroD1 with a reporter from a human EF-1α promoter using 2A peptides in a single tet-off lentiviral vector system. Briefly, hASC were transduced with the lentiviral vectors and allowed to differentiate into insulin-producing cells in vitro and in vivo. Thereafter, RNA expression, dithizone staining, and immunofluorescent analysis were conducted. RESULTS: Cleaved transcriptional factors from a single tet-off lentiviral vector were functionally equivalent to their native proteins and strictly regulated by doxycycline (Dox). Insulin gene expression in hASC transduced with Pdx1, Pdx1/ MafA, and Pdx1/NeuroD1 in differentiation medium were successfully increased by 1.89 ± 0.39, 4.81 ± 0.98, 5.51 ± 0.63, respectively, compared to venus-transduced, control hASC. These cells could form dithizone-positive cell clusters in vitro and were found to express insulin in vivo. CONCLUSION: Using our single tet-off lentiviral vector system, Pdx-1 and MafA/NeuroD1 could be simultaneously expressed in the absence of Dox. Further, this system allowed the differentiation of hASC into insulin-producing cells.

Rapid and sensitive mycoplasma detection system using image-based deep learning.

A major concern in the clinical application of cell therapy is the manufacturing cost of cell products, which mainly depends on quality control. The mycoplasma test, an important biological test in cell therapy, takes several weeks to detect a microorganism and is extremely expensive. Furthermore, the manual detection of mycoplasma from images requires high-level expertise. We hypothesized that a mycoplasma identification program using a convolutional neural network could reduce the test time and improve sensitivity. To this end, we developed a program comprising three parts (mycoplasma detection, prediction, and cell counting) that allows users to evaluate the sample and verify infected/non-infected cells identified by the program. In experiments conducted, stained DNA images of positive and negative control using mycoplasma-infected and non-infected Vero cells, respectively, were used as training data, and the program results were compared with those of conventional methods, such as manual counting based on visual observation. The minimum detectable mycoplasma contaminations for manual counting and the proposed program were 10 and 5 CFU (colony-forming unit), respectively, and the test time for manual counting was 20 times that for the proposed program. These results suggest that the proposed system can realize a low-cost and streamlined manufacturing process for cellular products in cell-based research and clinical applications.

Analysis of 2-aminopyridine labeled glycans by dual-mode online solid phase extraction for hydrophilic interaction and reversed-phase liquid chromatography.

Quantitative analysis of glycans released from glycoproteins using high-performance liquid chromatography (HPLC) requires fluorescent tag labeling to enhance sensitivity and selectivity. However, the methods required to remove large amounts of excess labeling reagents from the reaction mixture are time-consuming. Furthermore, these methods, including solvent extraction and solid phase extraction (SPE), often impair quantitative analysis. Here, we developed an online sample cleanup procedure for HPLC analysis of 2-aminopyridine (AP)-labeled glycans using a six-port/two-way valve and two small columns: one packed with a strong cation exchange resin (SCX) and the other comprising ODS silica gel. AP-labeled glycans delivered from an injection port were separated from excess AP by passing through an SCX column (4.6 mm i.d., 1 cm long) regulated to 40°C. The AP-labeled glycans were trapped on an ODS column (4.6 mm i.d., 1 cm long) to further separate them from inorganic contaminants. By changing the valve position after 2 min to connect the ODS column to an analysis column, AP-labeled glycans trapped in the ODS column were eluted with an acetonitrile-containing eluent followed by hydrophilic interaction liquid chromatography (HILIC) separation on an amide column or reversed-phase mode separation on a C30 column. This method was successfully used to analyze N-linked glycans released from several glycoprotein samples.

Adipose-derived stromal/stem cells improve epidermal homeostasis.

Wound healing is regulated by complex interactions between the keratinocytes and other cell types including fibroblasts. Recently, adipose-derived mesenchymal stromal/stem cells (ASCs) have been reported to influence wound healing positively via paracrine involvement. However, their roles in keratinocytes are still obscure. Therefore, investigation of the precise effects of ASCs on keratinocytes in an in vitro culture system is required. Our recent data indicate that the epidermal equivalents became thicker on a collagen vitrigel membrane co-cultured with human ASCs (hASCs). Co-culturing the human primary epidermal keratinocytes (HPEK) with hASCs on a collagen vitrigel membrane enhanced their abilities for cell proliferation and adhesion to the membrane but suppressed their differentiation suggesting that hASCs could maintain the undifferentiated status of HPEK. Contrarily, the effects of co-culture using polyethylene terephthalate or polycarbonate membranes for HPEK were completely opposite. These differences may depend on the protein permeability and/or structure of the membrane. Taken together, our data demonstrate that hASCs could be used as a substitute for fibroblasts in skin wound repair, aesthetic medicine, or tissue engineering. It is also important to note that a co-culture system using the collagen vitrigel membrane allows better understanding of the interactions between the keratinocytes and ASCs.

Tumorigenicity-associated characteristics of human iPS cell lines.

Human induced pluripotent stem cells (hiPSCs) represent promising raw materials of human cell-based therapeutic products (hCTPs). As undifferentiated hiPSCs exhibit intrinsic tumorigenicity properties that enable them to form teratomas, hCTPs containing residual undifferentiated hiPSCs may cause tumor formation following transplantation. We first established quantitative and sensitive tumorigenicity testing of hiPSCs dissociated into single cells using NOD/Shi-scid IL2Rγnull (NOG) mice by inhibiting apoptosis of hiPSCs with a Rho kinase inhibitor. To examine different features in tumorigenicity of various hiPSCs, 10 commonly available hiPSC lines were subjected to in vivo tumorigenicity testing. Transplanted hiPSC lines showed remarkable variation in tumor incidence, formation latency, and volumes. Most of the tumors formed were classified as immature teratomas. However, no signs of malignancies, such as carcinoma and sarcoma, were recognized in the tumors. Characteristics associated tumorigenicity of hiPSCs were investigated with microarray analysis, karyotype analysis, and whole exome sequencing. Gene expression profiling and pathway analysis supported different features of hiPSC lines in tumorigenicity. hiPSC lines showed chromosomal abnormalities in some lines and 61-77 variants of cancer-related genes carrying effective nonsynonymous mutations, which were confirmed in the COSMIC databases. In this study, the chromosomal abnormalities and cancer-related gene mutations observed in hiPSC lines did not lead to the malignancy of tumors derived from hiPSCs. Our results suggest that the potential tumorigenicity risk of hCTPs containing residual undifferentiated hiPSCs is dependent on not only amounts of undifferentiated hiPSCs but also features of the cell lines used as raw materials, a finding that should be considered from the perspective of quality of hCTPs used.

Report of the international conference on manufacturing and testing of pluripotent stem cells.

Sessions included an overview of past cell therapy (CT) conferences sponsored by the International Alliance for Biological Standardization (IABS). The sessions highlighted challenges in the field of human pluripotent stem cells (hPSCs) and also addressed specific points on manufacturing, bioanalytics and comparability, tumorigenicity testing, storage, and shipping. Panel discussions complemented the presentations. The conference concluded that a range of new standardization groups is emerging that could help the field, but ways must be found to ensure that these efforts are coordinated. In addition, there are opportunities for regulatory convergence starting with a gap analysis of existing guidelines to determine what might be missing and what issues might be creating divergence. More specific global regulatory guidance, preferably from WHO, would be welcome. IABS and the California Institute for Regenerative Medicine (CIRM) will explore with stakeholders the development of a practical and innovative road map to support early CT product (CTP) developers.

Notch Signaling Enhances Stemness by Regulating Metabolic Pathways Through Modifying p53, NF-κB, and HIF-1α.

Human adipose-derived mesenchymal stromal cells (hASCs) are attractive for regenerative medicine, but their limited in vitro life span limits their therapeutic applicability. Recent data demonstrate that hypoxia may benefit the ex vivo culture of stem cells. Such cells exhibit a high level of glycolytic metabolism under hypoxic conditions. However, the physiological role of glycolytic activation and its underlying regulatory mechanism are incompletely understood. We have shown that when activated under conditions of 5% O2, Notch signaling dramatically increases the rate of glycolysis, improves proliferation efficiency, prevents senescence, and maintains the multipotency of hASCs. In the present study, we found that activated Notch1 enhanced nuclear p65 levels, resulting in an increase in glucose metabolism through the upregulation of glycolytic factors, including GLUT3. Notch signaling was also involved in glucose metabolism through p53 inactivation. We also found that NF-κB signaling was regulated by p53. These data suggest that Notch-HES1 signaling enhances the glycolytic pathway through p53 and NF-κB. Our data also revealed that activated Notch1 markedly increased the transcriptional activity of hypoxia-inducible factor 1 (HIF-1). Knockdown of HIF-1α significantly attenuated glycolysis induced by activated Notch1, indicating that the glycolysis pathway is regulated by the coordination of Notch signaling and HIF. Overall, our observations provide new regulatory mechanisms for the glycolysis by Notch signaling to maintain the stemness of hASCs.

Scientific considerations for the regulatory evaluation of cell therapy products.

Cell therapy involves the administration of a viable somatic cell preparation to a patient for the treatment of a disease or traumatic damage. Because cell therapies are complex and very different from traditional biological products, they present significant challenges for regulatory authorities, manufacturers, developers, health care providers, and patients involved in their application. Like other emerging areas of biomedical research and development, there are many issues where regulatory views and decisions among countries and regions may differ due to minimal scientific evidence to support safety and efficacy, and lack of experience with these novel treatments. A brief overview of the current regulatory landscape for cell-based therapies is presented, and the need for a global effort to develop a set of common principles that may serve to facilitate the regulatory evaluation and market availability of these products is identified. In addition, a number of elements that could form a core consensus package of requirements for evaluating human cell therapy products is presented in the supplemental material which should be read in conjunction with the manuscript.

Plug-plug kinetic capillary electrophoresis for in-capillary exoglycosidase digestion as a profiling tool for the analysis of glycoprotein glycans.

An online exoglycosidase digestion was combined with a plug-plug kinetic mode of capillary electrophoresis (CE) for the analysis of glycoprotein-derived oligosaccharides. An exoglycosidase solution and a solution of glycoprotein glycans derivatized with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) were introduced to a neutrally coated capillary previously filled with electrophoresis buffer solution containing 0.5w/v% hydroxypropylcellulose. After immersion of both ends of the capillary in the buffer solutions, a negative voltage was applied for analysis. An APTS group of an oligosaccharide derivative has triply negative charges, which forced saccharide derivatives to anode with fast mobility and pass through the enzyme plug, which are detected at the anodic end. If the terminal monosaccharides of APTS-labeled oligosaccharides are released by the action of an exoglycosidase, the migration times of the oligosaccharides shift to those of digested oligosaccharides. We examined ß-galactosidase, α-mannosidase, ß-N-acetylhexosaminidase, α-neuraminidase, and α-fucosidase, and found only ß-galactosidase and α-neuraminidase showed good reactivity toward APTS-labeled oligosaccharides; the reaction was completed by injecting a 3.6cm long plug of 200 and 50mU/mL concentration of exoglycosidases. In contrast, other exoglycosidases could not react with APTS labeled oligosaccharides at a concentration up to 5U/mL. The ß-N-acetylhexosaminidase reaction was successively followed by the electrophoretic mobility of APTS oligosaccharides and stopped for 10min when saccharide derivatives were achieved in the enzyme plug. The reaction of α-fucosidase and α-mannosidase was completed by decreasing the electrophoretic voltage to -2kV when the APTS oligosaccharides were passing through an exoglycosidase plug. We established the CE conditions for all of the glycosidic linkage analysis of glycoprotein glycans.

BNIP3 upregulation via stimulation of ERK and JNK activity is required for the protection of keratinocytes from UVB-induced apoptosis.

The human skin has an important role in barrier function. Ultraviolet rays (UV) from sunlight exposure can cause cell apoptosis in the skin epidermis, resulting in the disruption of the barrier. Previously, we have demonstrated that BNIP3 stimulates autophagy in epidermal keratinocytes and has a protective effect in these cells upon UVB irradiation. In this study, we found that the accumulation of reactive oxygen species (ROS) by UVB irradiation was sufficient to trigger the activation of JNK and ERK mitogen-activated protein kinase (MAPK) in human primary epidermal keratinocytes. In turn, activated JNK and ERK MAPK mediated the upregulation of BNIP3 expression. Treatment with an antioxidant reagent or a specific inhibitor of MAPK, U0126, and a JNK inhibitor significantly attenuated the expression of BNIP3 triggered by UVB, followed by the induction of cell death by apoptosis. Furthermore, UVB-induced apoptosis was significantly stimulated by chloroquine or bafilomycin A1, an inhibitor of autophagy. Moreover, BNIP3 was required for the degradation of dysfunctional mitochondria upon UVB irradiation. These data clearly indicated that BNIP3-induced autophagy, which occurs via UVB-generated ROS-mediated JNK and ERK MAPK activation, has a crucial role in the protection of the skin epidermis against UVB irradiation.

Beneficial Effects of the Genus Aloe on Wound Healing, Cell Proliferation, and Differentiation of Epidermal Keratinocytes.

Aloe has been used as a folk medicine because it has several important therapeutic properties. These include wound and burn healing, and Aloe is now used in a variety of commercially available topical medications for wound healing and skin care. However, its effects on epidermal keratinocytes remain largely unclear. Our data indicated that both Aloe vera gel (AVG) and Cape aloe extract (CAE) significantly improved wound healing in human primary epidermal keratinocytes (HPEKs) and a human skin equivalent model. In addition, flow cytometry analysis revealed that cell surface expressions of ß1-, α6-, ß4-integrin, and E-cadherin increased in HPEKs treated with AVG and CAE. These increases may contribute to cell migration and wound healing. Treatment with Aloe also resulted in significant changes in cell-cycle progression and in increases in cell number. Aloe increased gene expression of differentiation markers in HPEKs, suggesting roles for AVG and CAE in the improvement of keratinocyte function. Furthermore, human skin epidermal equivalents developed from HPEKs with medium containing Aloe were thicker than control equivalents, indicating the effectiveness of Aloe on enhancing epidermal development. Based on these results, both AVG and CAE have benefits in wound healing and in treatment of rough skin.

Inhibitory Effects of Oligostilbenoids from the Bark of Shorea roxburghii on Malignant Melanoma Cell Growth: Implications for Novel Topical Anticancer Candidates.

Human malignant melanomas remain associated with dismal prognosis due to their resistance to apoptosis and chemotherapy. There is growing interest in plant oligostilbenoids owing to their pleiotropic biological activities, including anti-inflammatory, antioxidant, and anticancer effects. Recent studies have demonstrated that resveratrol, a well-known stilbenoid from red wine, exhibits cell cycle-disrupting and apoptosis-inducing activities on melanoma cells. The objective of our study was to evaluate the anti-melanoma effect of oligostilbenoids isolated from the bark of Shorea roxburghii. Among the isolates, four resveratrol oligomers, i.e., (-)-hopeaphenol, vaticanol B, hemsleyanol D, and (+)-α-viniferin, possessed more potent antiproliferative action than did resveratrol against SK-MEL-28 melanoma cells. Cell cycle analysis revealed that (-)-hopeaphenol, hemsleyanol D, and (+)-α-viniferin arrested cell division cycle at the G1 phase, whereas vaticanol B had little effect on the cell cycle. In addition, cell proliferation assay also revealed that (+)-α-viniferin induced DNA damage followed by induction of apoptosis in SK-MEL-28 cells, which was confirmed by an increased expression of γ-H2AX and cleaved caspase-3, respectively. The compounds vaticanol B, hemsleyanol D, and resveratrol significantly increased the expression of p21, suggesting that they are able to block cell cycle progression. Moreover, these oligostilbenoids downmodulated cylin D1 expression and extracellular signal-regulated kinase (ERK) activation. Furthermore, hemsleyanol D, (+)-α-viniferin, and resveratrol significantly decreased the expression of cyclin B1, which could also suppress cell cycle progression. The present study thus suggests that these plant oligostilbenoids are effective as therapeutic or chemopreventive agents against melanoma.

Aromatase Inhibitory Activity of Geranylated Coumarins, Mammeasins C and D, Isolated from the Flowers of Mammea siamensis.

A methanol extract of the flowers of Mammea siamensis (Calophyllaceae) was found to inhibit enzymatic activity against aromatase (IC50=16.5 µg/mL). From the extract, two new geranylated coumarins, mammeasins C (1) and D (2), were isolated together with seven coumarins: 8-hydroxy-5-methyl-7-(3,7-dimethyl-octa-2,6-dienyl)-9-(2-methyl-1-oxobutyl)-4,5-dihydropyrano[4,3,2-de]chromen-2-one (9), 8-hydroxy-5-methyl-7-(3,7-dimethyl-octa-2,6-dienyl)-9-(3-methyl-1-oxobutyl)-4,5-dihydropyrano[4,3,2-de]chromen-2-one (10), mammeas A/AA (14), A/AB (15), A/AA cyclo D (18), E/BA (23), and E/BC cyclo D (25). The structures of 1 and 2 were elucidated on the basis of spectroscopic evidence. Among the isolates including 17 previously reported coumarins, 1 (IC50=2.7 µM), 2 (3.6 µM), and mammea B/AB cyclo D (21, 3.1 µM) showed relatively strong inhibitory activities comparable to the activity of the synthetic nonsteroidal aromatase inhibitor aminoglutethimide (2.0 µM).

Report of the International Regulatory Forum on Human Cell Therapy and Gene Therapy Products.

The development of human cell therapy and gene therapy products has progressed internationally. Efforts have been made to address regulatory challenges in the evaluation of quality, efficacy, and safety of the products. In this forum, updates on the specific challenges in quality, efficacy, and safety of products in the view of international development were shared through the exchange of information and opinions among experts from regulatory authorities, academic institutions, and industry practitioners. Sessions identified specific/critical points to consider for the evaluation of human cell therapy and gene therapy products that are different from conventional biological products; common approaches and practices among regulatory regions were also shared. Certain elements of current international guidelines might not be appropriate to be applied to these products. Further, international discussion on the concept of potency and in vivo tumorigenicity studies, among others, is needed. This forum concluded that the continued collective actions are expected to promote international convergence of regulatory approaches of the products. The Pharmaceuticals and Medical Devices Agency and Japanese Society for Regenerative Medicine jointly convened the forum with support from the National Institutes of Biomedical Innovation, Health and Nutrition. Participants at the forum include 300 experts in and outside of Japan.

Neolignans from the Arils of Myristica fragrans as Potent Antagonists of CC Chemokine Receptor 3.

CC chemokine receptor 3 (CCR3) is expressed selectively in eosinophils, basophils, and some Th2 cells and plays a major role in allergic diseases. A methanol extract from the arils of Myristica fragrans inhibited CC chemokine ligand 11-induced chemotaxis in CCR3-expressing L1.2 cells at 100 µg/mL. From this extract, eight new neolignans, maceneolignans A-H (1-8), were isolated, and their stereostructures were elucidated from their spectroscopic values and chemical properties. Of those constituents, compounds 1, 4, 6, and 8 and (+)-erythro-(7S,8R)-Δ(8')-7-hydroxy-3,4-methylenedioxy-3',5'-dimethoxy-8-O-4'-neolignan (11), (-)-(8R)-Δ(8')-3,4-methylenedioxy-3',5'-dimethoxy-8-O-4'-neolignan (17), (+)-licarin A (20), nectandrin B (25), verrucosin (26), and myristicin (27) inhibited CCR3-mediated chemotaxis at a concentration of 1 µM. Among them, 1 (EC50 1.6 µM), 6 (1.5 µM), and 8 (1.4 µM) showed relatively strong activities, which were comparable to that of a synthetic CCR3 selective antagonist, SB328437 (0.78 µM).

Acylated oleanane-type triterpene saponins from the flowers of Bellis perennis show anti-proliferative activities against human digestive tract carcinoma cell lines.

Seven oleanane-type triterpene saponin bisdesmosides, perennisaponins N-T (1-7), were newly isolated from a methanol extract of daisy, the flowers of Bellis perennis L. (Asteraceae). The structures were determined based on chemical and physicochemical data and confirmed using previously isolated related compounds as references. The isolates, including 13 previously reported perennisaponins A-M (8-20), exhibited anti-proliferative activities against human digestive tract carcinoma HSC-2, HSC-4, and MKN-45 cells. Among them, perennisaponin O (2, IC50 = 11.2, 14.3, and 6.9 µM, respectively) showed relatively strong activities. The mechanism of action of 2 against HSC-2 was found to involve apoptotic cell death.

Simultaneous quantitative analysis of 12 methoxyflavones with melanogenesis inhibitory activity from the rhizomes of Kaempferia parviflora.

A methanol extract from the rhizomes of Kaempferia parviflora Wall. ex Baker (Zingiberaceae) has shown inhibitory effects against melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells (IC50 = 9.6 µg/mL). Among 25 flavonoids and three acetophenones isolated previously (1-28), several constituents including 5-hydroxy-7,3',4'-trimethoxyflavone (6, IC50 = 8.8 µM), 5,7,3',4'-tetramethoxyflavone (7, 8.6 µM), 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (12, 2.9 µM), and 5-hydroxy-3,7,3',4'-tetramethoxyflavone (13, 3.5 µM) showed inhibitory effects without notable cytotoxicity at the effective concentrations. Compounds 6, 7, 12, and 13 inhibited the expression of tyrosinase, tyrosine-related protein (TRP)-1, and TRP-2 mRNA, which could be the mechanism of their melanogenesis inhibitory activity. In addition, a quantitative analytical method for 12 methoxyflavones (1, 2, 4-11, 13, and 14) in the extract was developed using HPLC. The optimal condition for separation and detection of these constituents were achieved on an ODS column (3 µm particle size, 2.1 mm i.d. × 100 mm) with MeOH-0.1 % aqueous acetic acid solvent systems as the mobile phase, and the detection and quantitation limits of the method were estimated to be 0.08-0.66 ng and 0.22-2.00ng, respectively. The relative standard deviation values of intra- and interday precision were lower than 0.95 and 1.08 %, respectively, overall mean recoveries of all flavonoids were 97.9-102.9 %, and the correlation coefficients of all the calibration curves showed good linearity within the test ranges. For validation of the protocol, extracts of three kinds of the plant's rhizomes collected from different regions in Thailand (Leoi, Phetchabun, and Chiang Mai provinces) were evaluated. The results indicated that the assay was reproducible, precise, and could be readily utilized for the quality evaluation of the plant materials.

Capillary electrochromatography using monoamine- and triamine-bonded silica nanoparticles as pseudostationary phases.

Monoamine- and triamine-bonded silica nanoparticles were prepared using 3-aminopropyltrimethoxysilane and N(1)-(3-trimethoxysilylpropyl)diethylenetriamine, respectively, and used as pseudostationary phases for capillary electrochromatography. The amine-bonded silica nanoparticles were tightly adsorbed on the inner wall of a capillary and generated fast electro-osmotic flow (2.59 × 10(-4) cm(2) V(-1) s(-1)) toward the anode in an electric field. The electro-osmotic velocities obtained with 20 nm triamine-bonded silica were three to five times larger than those generated by a fused silica capillary and two times faster than those for the commercial cationic polymer-modified capillary. Fast electro-osmotic flow enables rapid analysis. This method was applied to hydrophilic interaction chromatography (HILIC) mode separation of various samples including the size separation of glucose oligomer derivatives and the resolution of four nucleic acid bases.

Overview: Core technical elements for early product development, evaluation, and control of human cell-based products.

Essential scientific elements for early product development, evaluation, and control of human cell-based products for cell therapy are addressed in a comprehensive and unifying way. Among them, donor issues (autologous and allogeneic), testing of raw materials, cell banking and cell substrate characterization, testing for adventitious agents (viral safety), and product sterility are very much related to each other. A significant amount of expertise exists in these areas both for traditional biologicals as well as for biotechnology products. Thus, core principles/concepts as well as the testing methodologies are already well defined. Other critical technical elements that are essential but need further discussion in terms of relevant regulatory requirements and testing methods are touched upon very briefly and followed by a detailed discussion (elsewhere).

Report of the international conference on regulatory endeavors towards the sound development of human cell therapy products.

The regulation of human cell therapy products is a key factor in their development and use to treat human diseases. In that regard, there is a recognized need for a global effort to develop a set of common principles that may serve to facilitate a convergence of regulatory approaches to ensure the smooth and efficient evaluation of products. This conference, with experts from regulatory agencies, industry, and academia, contributed to the process of developing such a document. Elements that could form a minimum consensus package of requirements for evaluating human cell therapy products were the overall focus of the conference. The important regulatory considerations that are unique to human cell therapy products were highlighted. Sessions addressed specific points that are different from those of traditional biological/biotechnological protein products. Panel discussions complemented the presentations. The conference concluded that most of the current regulatory framework is appropriate for cell therapy, but there are some areas where the application of the requirements for traditional biologicals is inappropriate. In addition, it was agreed that there is a need for international consensus on core regulatory elements, and that one of the major international organizations should take the lead in formulating such a consensus document.