Platelet-rich plasma (PRP) is the cell free plasma, which has an enriched concentration of platelets and clotting factors with the ability to enhance the natural healing process. PRP is often used by physicians in an office setting to accelerate the healing of a variety of sports related injuries, chronic wounds and enhance skin rejuvenation. PRP mimics the wound healing cascade by enhancing the recruitment, proliferation and differentiation of cells involved in tissue regeneration. Although PRP is used to enhance healing, the efficacy thereof is debated as no clear-cut set of parameters is available that device manufacturers and protocols should follow. The lack of uniformity in the PRP preparation methods results in differing PRP volume, platelet contents and unavoidably platelet-derived growth factors. Therefore, the aim of this study was to develop a simple and rapid method for preparing autologous PRP in an office setting using a tabletop centrifuge for point-of-care use. The simplified preparation procedure involved a single centrifugation step of 18 ml of whole blood, which sufficiently enriched the platelet content in the PRP fraction. As activated platelets express and release growth factors and cytokines that mediate the different phases of the wound healing cascade, the extracted PRP fraction was activated with an ethanol, calcium chloride (CaCl2) and platelet poor plasma (PPP) preparation in glass containers, without the collection of additional blood as required in some protocols. The activated PRP formed a fibrin clot, trapping the degranulating platelets and its released growth factors. The concentration of TGF- 1 obtained from the fibrin clot was 45.49 ± 3.80 ng/ml, in range with the available literature. During the in vitro studies, the extracted PRP by the developed method was able to significantly induce cell proliferation in a dose dependent manner. Cells enumerated with the crystal violet assay indicated that the cells treaded with 5% or 10% PRP significantly increased the percentage of viable cells to 165-176% and 156-158%, when compared to the positive controls. Cells enumerated with the MTT-assay indicated that the cells treaded with 5% or 10% PRP increased the percentage of viable cells to 79-91% and 87-105% which is comparable to that of the positive control. Data from the cellular proliferation assays indicate that sufficient plateletderived growth factors had been obtained with the preparation procedure. Furthermore, data from the in vivo studies indicated that the extracted PRP was able to augment soft tissue regeneration and bone formation. Treatment with the activated PRP resulted in symptom reduction and accelerated healing of various injuries. The simplified preparation and the use of the provided study product packaged in a kit developed during this study will enable physicians to easily obtain autologous PRP, in an office setting for point-of-care use, with the ability to induce tissue regeneration. / Dissertation (MSc)--University of Pretoria, 2013 / gm2014 / Pharmacology / unrestricted

A utilização de células humanas para a produção do fator VIII de coagulação recombinante (rFVIII) visa obter padrões de glicosilação equivalentes aos encontrados na proteína normal. O objetivo do trabalho foi obter um processo de produção do rFVIII em biorreator em perfusão, devido à sua labilidade térmica. Foram realizados estudos preliminares em Spinner e biorreator utilizando uma linhagem de rHeLa, cujos resultados embasaram os estudos com a linhagem produtora rSkHep. Foram utilizados microcarregadores nos cultivos com esta linhagem devido à dificuldade de adaptação da mesma à suspensão. Ensaios preliminares identificaram a melhor condição de cultivo com 3 g/L Mic e 1 cel/mic e, a partir destes valores, realizou-se um ensaio em perfusão, com tempo de residência de 24 h, no qual as variáveis controladas foram mantidas constantes durante três tempos de residência. A concentração de rFVIII obtida foi semelhante 2 UI/ mL. / The interest in using human cells for the recombinant coagulation factor VIII (rFVIII) lies in obtaining glycosylation patterns similar to the ones found in the normal protein. The objective of this work was to obtain a process for rFVIII production in bioreactor, in perfusion mode, due to the thermal lability of the protein. Using a recombinant HeLa cell line adapted to suspension growth a group of studies in a bioreactor in batch mode were performed. These results were the basis for the studies performed with the producing cell line rSkHep. Microcarriers (micc) were used due to the harshness to adapt the cell line to suspension and to serum-free medium. Preliminary tests identified the best culture condition with 3 g micc/L and 3 cell/micc and, from its values, it was performed a bioreactor study in perfusion mode, with a residence time of 24 hours. The controlled variables were kept constant for three residence times. The maximum rFVIII concentration obtained was 2 UI/mL.

O fator VIII da coagulação é utilizado para o tratamento da hemofilia A e pode ser obtido a partir de concentrados do plasma humano ou na sua forma recombinante (rFVIII). Nosso laboratório tem explorado uma alternativa mais eficiente para a produção do rFVIII em células de mamíferos, utilizando um variante artificial do rFVIII humano (rFVIII-lab). O objetivo principal deste trabalho foi avaliar a imunogenicidade do rFVIII-lab utilizando camundongos modelo da hemofilia A, tendo como objetivos experimentais a purificação, caracterização de atividade funcional in vivo e caracterização de imunogenicidade do rFVIII-lab comparada a produtos de referência, um derivado de plasma e outro recombinante. Os resultados indicam que o perfil de imunogenicidade observado para o rFVIII-lab foi menos intenso e a atividade funcional observada foi similar quando comparado aos produtos de referência. A expectativa é que o presente estudo contribua para o estabelecimento de uma plataforma de produção do rFVIII no país visando o tratamento dos pacientes hemofílicos brasileiros. / Factor VIII (FVIII) replacement therapy employing either FVIII concentrates from blood plasma or recombinant FVIII is the standard of care for management of hemophilia A. Our group has been exploring a more efficient alternative for recombinant FVIII production in mammalian cells employing an engineered artificial variant of the protein (rFVIII-lab). The main objective of this study was to evaluate the immunogenicity of the rFVIII-lab using a murine model of hemophilia A and the specific experimental objectives were to purify, evaluate the in vivo functional activity and the immunogenicity of rFVIII-lab compared to plasma derived and recombinant reference products. Data revealed reduced immunogenicity of rFVIII-lab whereas functional activity was similar when compared to the reference products. The presented study is expected to contribute to the establishment of a locally production platform for the rFVIII aiming at the treatment of Brazilian hemophilic patients.

A utilização de células humanas para a produção do fator VIII de coagulação recombinante (rFVIII) visa obter padrões de glicosilação equivalentes aos encontrados na proteína normal. O objetivo do trabalho foi obter um processo de produção do rFVIII em biorreator em perfusão, devido à sua labilidade térmica. Foram realizados estudos preliminares em Spinner e biorreator utilizando uma linhagem de rHeLa, cujos resultados embasaram os estudos com a linhagem produtora rSkHep. Foram utilizados microcarregadores nos cultivos com esta linhagem devido à dificuldade de adaptação da mesma à suspensão. Ensaios preliminares identificaram a melhor condição de cultivo com 3 g/L Mic e 1 cel/mic e, a partir destes valores, realizou-se um ensaio em perfusão, com tempo de residência de 24 h, no qual as variáveis controladas foram mantidas constantes durante três tempos de residência. A concentração de rFVIII obtida foi semelhante 2 UI/ mL. / The interest in using human cells for the recombinant coagulation factor VIII (rFVIII) lies in obtaining glycosylation patterns similar to the ones found in the normal protein. The objective of this work was to obtain a process for rFVIII production in bioreactor, in perfusion mode, due to the thermal lability of the protein. Using a recombinant HeLa cell line adapted to suspension growth a group of studies in a bioreactor in batch mode were performed. These results were the basis for the studies performed with the producing cell line rSkHep. Microcarriers (micc) were used due to the harshness to adapt the cell line to suspension and to serum-free medium. Preliminary tests identified the best culture condition with 3 g micc/L and 3 cell/micc and, from its values, it was performed a bioreactor study in perfusion mode, with a residence time of 24 hours. The controlled variables were kept constant for three residence times. The maximum rFVIII concentration obtained was 2 UI/mL.

O fator VIII da coagulação é utilizado para o tratamento da hemofilia A e pode ser obtido a partir de concentrados do plasma humano ou na sua forma recombinante (rFVIII). Nosso laboratório tem explorado uma alternativa mais eficiente para a produção do rFVIII em células de mamíferos, utilizando um variante artificial do rFVIII humano (rFVIII-lab). O objetivo principal deste trabalho foi avaliar a imunogenicidade do rFVIII-lab utilizando camundongos modelo da hemofilia A, tendo como objetivos experimentais a purificação, caracterização de atividade funcional in vivo e caracterização de imunogenicidade do rFVIII-lab comparada a produtos de referência, um derivado de plasma e outro recombinante. Os resultados indicam que o perfil de imunogenicidade observado para o rFVIII-lab foi menos intenso e a atividade funcional observada foi similar quando comparado aos produtos de referência. A expectativa é que o presente estudo contribua para o estabelecimento de uma plataforma de produção do rFVIII no país visando o tratamento dos pacientes hemofílicos brasileiros. / Factor VIII (FVIII) replacement therapy employing either FVIII concentrates from blood plasma or recombinant FVIII is the standard of care for management of hemophilia A. Our group has been exploring a more efficient alternative for recombinant FVIII production in mammalian cells employing an engineered artificial variant of the protein (rFVIII-lab). The main objective of this study was to evaluate the immunogenicity of the rFVIII-lab using a murine model of hemophilia A and the specific experimental objectives were to purify, evaluate the in vivo functional activity and the immunogenicity of rFVIII-lab compared to plasma derived and recombinant reference products. Data revealed reduced immunogenicity of rFVIII-lab whereas functional activity was similar when compared to the reference products. The presented study is expected to contribute to the establishment of a locally production platform for the rFVIII aiming at the treatment of Brazilian hemophilic patients.