Efeitos de nanopartículas de prata em células de osso e pulmão humano

Mestrado em Biologia AplicadaAs nanopartículas são definidas como partículas com dimensão entre 1 - 100 nm, resultando em propriedades únicas que podem ser úteis em diversas áreas. As AgNP são as nanopartículas mais utilizadas em produtos comerciais, como: curativos, cateteres, próteses, cosméticos, têxteis e produção de alimentos, devido à sua atividade antimicrobiana. As propriedades físico-químicas únicas inerentes às NPs enfatizam a necessidade de uma avaliação adequada dos potenciais efeitos tóxicos, já que suas interacções com sistemas biológicos, bem como o seu destino ambiental são imprevisíveis. As propriedades da superfície das NPs são de importância essencial para a sua capacidade de agregação, influenciando na mobilidade e absorção celular. Neste estudo, avaliaram-se os efeitos tóxicos de AgNPs não revestidas e revestidas, na viabilidade das linhas celulares de osteossarcoma (MG-63) e adenocarcinoma do pulmão (A549). Para isso, células cultivadas in vitro foram expostas a concentrações crescentes de AgNPs até 400μg/ml (não revestidas - <100nm) e até 100ug/ml (revestidas com PVP – 10 e 20nm), durante 24h e 48h. O crescimento celular e morfologia foram observados diariamente, utilizando um microscópio invertido e a viabilidade celular foi medida pelo ensaio MTT. Para AgNPs não revestidas (24h e 48h), os ensaios de MTT e Trypan Blue, revelam uma disparidade de resultados sendo, ambos inconclusivos. No entanto, para as AgNPs revestidas, os ensaios de MTT independentes, mostraram resultados consistentes e fiáveis, com uma diminuição significativa da viabilidade celular a 50μg/ml. As AgNPs também modulam a distribuição do ciclo celular através da acumulação de células em G2/M, e concomitante diminuição de células em G0/G1, juntamente com o aumento da apoptose. Em conjunto, estes resultados sugerem que AgNPs induzem toxicidade, apoptose e paragem do ciclo celular em G2, nas linhas celulares A549 e MG-63.Nanoparticles are defined as particles with at least one dimension between 1 – 100nm and this small size results in unique properties that can be useful in a range of fields. Silver nanoparticles (AgNPs) are the most widely used nanoparticles in commercial products, viz wound dressings, catheters, prosthesis, cosmetics, textiles and food production, due to their antimicrobial activity. The unique physicochemical properties of NPs emphasize the need for proper assessment of the potential toxic effects, since their unpredicted interactions with biological systems and environmental fate. The surface properties of NPs are of essential importance for their aggregation behavior, and this influences their mobility in environmental partitions and cellular uptake. In this study, we evaluated the toxic effects of uncoated and coated AgNP on the viability osteosarcoma (MG-63) and lung (A549) cell lines. For this, in vitro cultured cells were exposed to different increasing concentrations of AgNPs up to 400μg/mL (uncoated - <100nm) and up to 100μg/ml (PVP coated – 10 and 20nm) for 24h and 48h. Cell growth and morphology was daily observed using an inverted microscope and cell viability was measured by MTT reduction assay. For uncoated AgNPs (24h and 48h), MTT assays and Trypan Blue and reveal a disparity of results being both inconclusive. However, for the coated AgNPs, independent MTT assays showed consistent and reliable results, with a significant decrease in cell viability at the 50μg/ml. AgNPs also modulated cell cycle distribution through the accumulation of cells at G2/M and a concurrent decrease in cells at G0/G1 along with the increase on apoptotic cells. This effect was observed in both cell lines. Together, these results suggest that AgNPs induce toxicity, apoptosis and G2 cell cycle arrest in A549 and MG-63 cells

Minuto Saúde: a produção de podcasts no meio acadêmico

Introdução: No mundo globalizado, a divulgação de informações ocorre de forma instantânea por meio de mídias digitais. Tal propagação de informações se tornou ainda mais evidente no período pós pandêmico. Nesse sentido, assuntos relacionados à saúde geram muitas dúvidas na população, e podcasts que esclareçam tais dúvidas, podem ser grandes aliados para a divulgação de informações relevantes de cunho científico. Método: Trata-se de um relato de experiência, resultado de um projeto de extensão de uma instituição de ensino superior. O projeto foi realizado no período de fevereiro a agosto de 2023, no município de Belo Horizonte, Minas Gerais. A produção do podcast foi desenvolvida em três etapas, sendo elas: o planejamento e embasamento teórico; a elaboração de roteiros e gravação dos episódios; e, por fim, sua divulgação na plataforma Spotify. Resultados e Discussão: Foram produzidas quatro temporadas de conteúdos na área da saúde, denominadas, Prevenção das hepatites, da anemia, da obesidade e agosto dourado, contendo dois episódios em cada uma delas, totalizando oito episódios. As análises obtidas revelaram maior audiência relacionada a temporada 1. Considerações finais: Ressalta-se que o uso dos podcasts socializam a divulgação de informações, o que favorece a educação em saúde e empoderamento da população quanto ao uso dessas informações de forma adequada

Unraveling pathways of cyto and genotoxicity of AgNP in lung and bone cells: in vitro and in vivo approach

Silver nanoparticles (AgNPs) have been extensively used due to their antimicrobial and anti-inflammatory properties. The unique properties have been exploited in a wide range of fields, such as, medical, scientific, industrial, and consumer products allowing the exposure through various routes including inhalation, ingestion and dermal. Although, is still not clear whether their toxicity is attributed to AgNPs intrinsic toxicity and/or from the released ions and their fate and behavior in the organism. Therefore, this study was sub-divided in two main hypothesis a) Small differences on AgNPs size enough to induce different toxicity profiles in in vitro lung and bone cells. b) The toxicity, distribution and excretion kinetics AgNPs after inhalation are size. Therefore, in the in vitro work, A549 and MG-63 cell lines were exposed to AgNPs with a diameter of 10 nm (AgNP10) and 20 nm (AgNP20) (up to 100μg/mL), as well as ionic silver (AgNO3). The effects on cell viability, proliferation, induced apoptosis, DNA damage and cell cycle dynamics were assessed. Also, the contribution of ionic silver (due to AgNP dissociation) on the toxicity of AgNPs was determined. Results for A549 cell line showed that for concentrations 50μg/mL, AgNP10 induced severe DNA damage (comet class 3-4), cell cycle arrest at G2 and induction of late-apoptosis. Contrarily, AgNP20 induced arrest at S phase and increase in the % sub-G1, that was not recovered after 48h. AgNP20 also induced late-apoptosis/necrosis. MG-63 results, showed that AgNPs10 are more reactive and prone to form large aggregates in α-MEM medium. AgNP20 were found to induce a cell cycle arrest at G0/G1 and apoptosis, while AgNP10 did not induce a cytostatic effect, but rather induced necrosis. Finally, combining both A549 and MG-63 results, we concluded that A549 are more sensitive to AgNPs than MG-63, and that small difference in AgNP size is enough to induce different responses in both cell lines. AgNO3 in short exposure (48h) to is more toxic compared to AgNPs, however, when exposure lasts longer we observed that, the AgNPs turn out being more toxic. A completed characterization of the particles, before the toxicity assessment is crucial to understand AgNPs effects in different cell lines. AgNPs toxicity cannot be attributed to the dissociated Ag+ alone. AgNPs toxicity for A549 it is highly dependent on size and concentration of the AgNPs. For MG-63 cell line the size dependent AgNPs toxicity may be associated in part with the NPs interference with the cell membranes and consequent uptake/adsorption processes. Silver toxicity, distribution and excretion of two different sizes of AgNPs (5 and 50nm) and ionic silver (AgNO3) were assessed in mice. Two experiments were performed: A) acute exposure - endpoint evaluation after 1 or 2 intratracheal instillation (IT) and B) chronic exposure - endpoint evaluation after repeated ITs, once a week for 5 weeks. Mice were allowed to recover for 1, 2, 7, 14, 21 or 28 days after the last instillation (dpi). At the end of both studies, blood samples were collected for hematology, and the organs (brain, lung, liver, heart, spleen and kidney), urine and feces were collected to evaluate the silver concentration by ICP-MS. Lung and liver tissues were collected to GSH analysis. For the acute study only, lung tissues were collected to study the effects on the metabolic profile by NMR and for the chronic study only, data was gathered to build a PBPK model. Overall, for the acute study the effects of the instilled AgNPs were dependent on size and number of instillations. The AgNP5 shared a similar inflammatory effect with AgNO3, while AgNP50, seems to have higher influence on the innate immune system. Regarding the biodistribution results, the highest concentration of silver obtained was in the lungs, followed by blood, spleen, kidneys and liver. AgNP5 showed a faster and higher distribution to all organs, whereas larger particles remained mostly in the blood and only a small fraction was obtained in the organs. AgNP50 showed higher excretion, as evaluated by higher silver levels in the urine and faeces of AgNP50-exposed animals. After 2 IT of AgNPs or AgNO3, the lungs of exposed mice showed increased GSSG levels and a, suggesting an oxidative stress response. GSH was increased in the liver after 1 IT with AgNP50 or AgNO3, which could be related to biliary excretion of silver as Ag-GSH complex. NMR profiling of lung tissues revealed several Ag-induced alterations in metabolites involved in different pathways, such as glycolysis and TCA cycle amino acid metabolism, phospholipid metabolism and antioxidant defense. Notably, most of the metabolic changes observed after 1 IT were either absent or reversed in animals subjected to 2 IT, suggesting adaptation mechanisms to cope with the initial insult and recover homeostasis. Additionally, AgNO3 showed no significant alterations after 2 IT. For the chronic study, haematology results showed that AgNP5 induced higher toxicity to RBC, neutrophils and basophils which indicate an inflammatory reaction, while AgNP50 showed eosinophilia and possible blockage in the monocyte-macrophage differentiation. Overall, after chronic exposures the GSSG:Total GSH ratio was increased in the lung for 14 and 21 dpi, while in the liver there was an increase in the GSSG:Total GSH ratio shortly after 1 and 2 dpi for AgNPs, followed by a decrease at 14 and 21 dpi, for all treatments. The major route for excretion seems to be through the urine, despite a high concentration of AgNP5 was also found in faeces. A Physiologically based pharmacokinetic (PBPK) model from 7 specific tissues proved to be successful for the heart, liver and kidney compartments with the modelled silver concentrations in line with the in vivo data. Overall, this study suggests that even small differences on AgNPs size are enough to induce different outcomes and effects in human cell lines. Additionally, when comparing bigger sizes differences, along with the size, the number of exposures seems to play a role in the AgNPs effects, distribution and elimination from the body.status: publishe

Revelando as vias de cito e genotoxicidade de AgNP em células de pulmão e osso: abordagem in vitro e in vivo

Silver nanoparticles (AgNPs) have been extensively used due to their antimicrobial and anti-inflammatory properties. The unique properties have been exploited in a wide range of fields, such as, medical, scientific, industrial, and in consumer products allowing the exposure through various routes including inhalation, ingestion and dermal. Although, there are many studies reporting the effects of AgNPs, is still not clear whether their toxicity is attributed to AgNPs intrinsic toxicity and/or from the released ions. Therefore, this study was sub-divided in two main hypotheses: A) small differences on AgNPs size enough to induce different toxicity profiles in lung (cell line A549) and bone cells (cell line MG-63) grown in vitro; B) the toxicity, distribution and excretion kinetics AgNPs upon instilled mice in vivo is size dependent. Therefore, in the in vitro studies, A549 and MG-63 cell lines were exposed to AgNPs with 10 nm (AgNP10) and 20 nm (AgNP20) (up to 100μg/mL), as well as ionic silver (as AgNO3). The effects on cell viability, proliferation, induced apoptosis, DNA damage and cell cycle dynamics were assessed. Also, the contribution of ionic silver (due to AgNP dissociation) on the toxicity of AgNPs was determined. Results for A549 cell line showed that for concentrations 50μg/mL. Also, for doses >50μg/mL, AgNP10 induced severe DNA damage (comet class 3-4), cell cycle arrest at G2 and induction of late-apoptosis. AgNP20 induced arrest at S phase and increase in the % sub-G1, that was not recovered after 48h. AgNP20 also induced late-apoptosis/necrosis. MG-63 results showed that AgNP20 induced cell cycle arrest at G0/G1 and decrease in cell proliferation, while AgNP10 induced severe DNA damage which lead to death by necrosis. Finally, combining both A549 and MG-63 results, we concluded that A549 are more sensitive to AgNPs and the toxicity was highly dependent on size and concentration. Additionally, a small difference in AgNP size is enough to induce a size-dependent toxicity in both cell lines, but it was not enough to influence the uptake rate by both cell lines. AgNO3 in short exposure (48h) is more toxic compared to AgNPs, however, for longer exposures AgNPs shown higher toxicity completely inhibiting cell growth. Silver toxicity, distribution and excretion of two different sizes of AgNPs (5 and 50nm) and ionic silver (AgNO3) were assessed in vivo in mice. Two experiments were performed: A) acute exposure - endpoint evaluation after 1 or 2 intratracheal instillation (IT) and recovery for 7 days; B) chronic exposure - endpoint evaluation after repeated ITs, once a week for 5 weeks. Mice were allowed to recover for 1, 2, 7, 14, 21 or 28 days after the last instillation (dpi). At the end of both studies, blood samples were collected for hematology, and the organs (brain, lung, liver, heart, spleen and kidney), urine and feces were collected to evaluate the silver concentration by ICP-MS. Lung and liver tissues were collected to GSH analysis. For the acute study only, lung tissues were collected to study the effects on the metabolic profile by NMR and for the chronic study, data was gathered to build a Physiologically based pharmacokinetic (PBPK) model. Overall, for the acute study the effects of the instilled AgNPs were dependent on size and number of instillations. The AgNP5 shared a similar inflammatory effect with AgNO3, while AgNP50, seemed to have higher influence on the innate immune system. Regarding the biodistribution results, the highest concentration of silver obtained was in the lungs, followed by blood, spleen, kidneys and liver. AgNP5 showed a faster and higher distribution to all organs but with a high rate of accumulation. The AgNP50 remained mostly in the blood with only a small fraction of silver detected in the organs, although, the small concentration of silver distributed to the organs, presented a high rate of excretion. After 2 IT of AgNPs or AgNO3, the redox state of the lungs suggested an oxidative stress response correlated to higher amounts of silver. In the liver, there was an increase in GSH for AgNP50 or AgNO3, which could be related to biliary excretion of silver as Ag-GSH complex. NMR profiling of lung tissues revealed several Ag-induced alterations in metabolites involved in different pathways, such as glycolysis and TCA cycle amino acid metabolism, phospholipid metabolism and antioxidant defense. Notably, most of the metabolic changes observed after 1 IT were reversed in animals subjected to 2 IT of AgNPs, suggesting adaptation mechanisms to recover homeostasis. Additionally, AgNO3 showed no significant alterations after 2 IT. For the chronic study, hematology results showed that AgNP5 induced major and longer lasting toxicity compared to AgNP50 and AgNO3. The redox state of both lung and liver, overall, showed an oxidative stress response which could be related to the silver exposure. The major route for excretion seems to be through the urine, especially for AgNP50 and AgNO3. Also, a high concentration of AgNP5 was also found in feces. The PBPK model was not successful predicting the real distribution of particles from 5 – 50nm. From the 7 specific tissues, the modelled data for the heart and liver were in line with the in vivo data. Overall, this study suggests that even small differences on AgNPs size are enough to induce different outcomes and effects in human cell lines. Additionally, when comparing bigger sizes differences, along with the size, the number of exposures seems to play a role in the AgNPs effects, distribution and elimination from the body.As nanopartículas de prata (AgNPs) têm sido amplamente utilizadas devido às suas propriedades antimicrobianas e anti-inflamatórias. Em virtude das suas propriedades únicas, as AgNPs têm vindo a ser incorporadas numa vasta gama de setores, tais como, na ciência, na medicina, na indústria e em diversos produtos de consumo, presentes no nosso dia-a-dia. Esta ubiquidade conduz à possibilidade de exposição através de várias vias, sobretudo, pela via inalatória, oral e dérmica. Embora existam diversos estudos que reportam os efeitos das AgNPs, ainda não é claro se a sua toxicidade é intrínseca ou originada pela libertação de iões de prata. Assim, neste estudo são propostas duas hipóteses: A) pequenas diferenças no tamanho das AgNPs são suficientes para induzir diferentes perfis de toxicidade em células de pulmão (linha celular A549) e osso (linha celular MG-63) in vitro; B) a toxicidade, distribuição e excreção das AgNPs é condicionada pelo tamanho, após-instilação in vivo em ratinhos. Nos estudos in vitro, as linhas celulares foram expostas a AgNPs com 10nm (AgNP10) e 20nm (AgNP20) (até 100 μg/mL), bem como à prata iónica (na forma de AgNO3). Após exposição foram estudados diferentes parâmetros, tais como, a internalização das AgNPs pelas linhas celulares, a viabilidade celular e proliferação, alterações na dinâmica do ciclo celular, indução de micronúcleos e a morte celular por apoptose e/ou necrose. Além disso, estudou-se a contribuição da prata iónica na toxicidade das AgNPs nas células. Os resultados da linha celular A549 mostraram que as AgNP20 reduziram a actividade metabólica para doses 50 μg/mL. Também para doses > 50 μg/mL, AgNP10 induziu dano severo no DNA (cometa classe 3-4), paragem do ciclo celular em G2 e indução de apoptose tardia. AgNP20 induziu paragem na fase S e aumentou a % sub-G1 após 24h de exposição, efeito que se manteve após 48h de exposição. Este tamanho induziu também apoptose tardia/necrose nas células A549. Os resultados de MG-63 mostraram que as AgNP20 induziram a paragem do ciclo celular em G0/G1 e diminuição da proliferação celular, enquanto que as AgNP10 induziram um dano severo no DNA, levando a morte por necrose. Combinando os resultados de A549 e MG-63, concluíu-se que a linha celular A549 é mais sensível às AgNPs e que a toxicidade foi dependente do tamanho e da concentração utilizadas. Concluiu-se, ainda que, uma pequena diferença no tamanho de AgNPs foi suficiente para induzir diferentes respostas em ambas as linhas celulares, mas não foi suficiente para influenciar a taxa de internalização. O AgNO3 induziu maior toxicidade do que as AgNPs em curtas exposições (48h), contudo, a longo prazo, observou-se que, as AgNPs se tornaram mais tóxicas, inibindo completamente o crescimento de ambas linhas celulares. Nos estudos in vivo, avaliou-se a toxicidade, distribuição e excreção de prata de dois tamanhos diferentes de AgNPs (5 e 50nm) e prata iónica (AgNO3) em ratinhos. Foram realizados dois ensaios: A) exposição aguda - após 1 ou 2 instilações intratraqueais (IT) e recuperação durante 7 dias; B) exposição crónica - após repetidas ITs, administradas uma vez por semana durante 5 semanas. Neste ensaio, os animais recuperaram por 1, 2, 7, 14, 21 ou 28 dias após a última instilação (dpi). No final de ambos os estudos, foram recolhidas amostras de sangue para hematologia, e respetivos órgãos (cérebro, pulmão, fígado, coração, baço e rim), assim como, urina e fezes para avaliação da concentração de prata por ICP-MS. Tecidos de pulmão e fígado foram recolhidos para análises de GSH/GSSG. No estudo agudo, tecidos de pulmão foram ainda recolhidos para avaliar os efeitos no perfil metabólico por RMN e no estudo crónico, os dados recolhidos foram utilizados para construir um modelo farmacocinético baseado na fisiologia (PBPK). Em geral, no estudo agudo, os efeitos das AgNP instiladas mostraram ser dependentes do tamanho e do número de instilações. Sendo que as AgNP5 induziram um efeito inflamatório semelhante a AgNO3, enquanto que as AgNP50 mostraram ter maior influência no sistema imunitário inato. Quanto aos resultados da biodistribuição, a maior concentração de prata foi obtida nos pulmões, seguida de sangue, baço, rins e fígado. Mais especificamente, a AgNP5 mostrou uma distribuição mais rápida, mas também uma maior taxa de acumulação. Enquanto que as AgNP50 permaneceram maioritariamente no sangue com apenas uma pequena percentagem de prata distribuída para os órgãos, apesar disso, a quantidade de prata distribuída para os órgãos, apresentou uma alta taxa de excreção. Após 2 IT de AgNPs ou AgNO3, o estado redox do pulmão sugere uma resposta a stress oxidativo, correlacionada com o aumento de prata no pulmão. A GSH no fígado aumentou após 1 IT de AgNP50 e AgNO3, podendo estar relacionado à excreção biliar de prata como complexo Ag-GSH. O perfil metabólico dos tecidos pulmonares revelou uma série de alterações induzidas por Ag em metabolitos envolvidos em diferentes vias, como, glicólise, metabolismo do ciclo de Krebs, metabolismo de fosfolípidos e defesa antioxidante. Notavelmente, a maioria das alterações metabólicas observadas após 1 TI foram recuperadas ou alteradas nos animais submetidos a 2 IT, sugerindo mecanismos de adaptação para lidar com o insulto inicial e recuperar a homeostase. Adicionalmente, a exposição a AgNO3 não mostrou alterações significativas após 2 IT. Para o estudo crónico, os resultados da hematologia mostraram que as AgNP5 induziram uma toxicidade mais severa e por um maior período de tempo, comparado com AgNP50 e AgNO3. Em geral, após exposição crónica, o estado redox do pulmão e fígado mostrou indução de stress oxidativo que poderá estar relacionado com a exposição a prata. Os níveis de prata diminuíram ao longo do tempo nos órgãos dos animais tratados com AgNP50 e AgNO3, enquanto que nos ratinhos expostos a AgNP5, os níveis de prata apresentaram-se mais altos a 28 dpi, no pulmão, baço, rim, fígado e sangue. A principal via de excreção pareceu ser através da urina, especialmente para AgNP50 e AgNO3. Uma alta concentração de AgNP5 também foi verificada nas fezes. O modelo PBPK não se mostrou eficiente na previsão da distribuição de AgNPs com tamanho entre 5-50 nm. Para os 7 tecidos avaliados, os resultados do PBPK foram concordantes com os dados in vivo apenas para o coração e fígado. Em geral, este estudo sugere que pequenas diferenças no tamanho entre AgNPs são suficientes para induzir diferentes efeitos em linhas celulares humanas. Contudo, ao comparar diferenças de tamanhos maiores, para além do tamanho, o número de exposições parece desempenhar um papel nos efeitos, distribuição e eliminação das AgNPsPrograma Doutoral em Biologi

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved