Neste trabalho foram estudadas as interações entre os corantes ciânicos com dois cromóforos (BCD) e monocamadas de Langmuir de fosfolipídio (DPPC). Devido ao alto coeficiente de absorção molar da luz na região ? > 600 nm, ao alto rendimento quântico do estado tripleto, à alta fotocitotoxicidade e à alta afinidade com estruturas celulares os BCD são promissores para serem utilizados em terapia fotodinâmica. Os estudos das características da interação de BCD com a monocamada são importantes tanto para esclarecer os efeitos estruturais na interação de monocamadas com outras moléculas quanto para suas aplicações em terapia fotodinâmica e em outras áreas tecnológicas tais como nanoeletrônica, fotônica etc. As isotermas de pressão superficial (?-A) obtidas mostram que os BCD e as monocamadas interagem, pois as isotermas (?-A) se expandem conforme é aumentado à porcentagem de BCD. Esta interação é dependente tanto da estrutura do BCD quanto da força iônica da subfase. A partir das isotermas (?-A) foi obtido o módulo de compressibilidade (Cs-1 = -A (??/?A) das monocamadas, do qual foram analisadas, de maneira mais detalhada, as modificações da monocamada de DPPC devido à presença dos BCD. Estas modificações compreendem o aparecimento da fase líquida expandida (LE) e formação dos domínios antecipada em comparação com a monocamada de DPPC puro. Foi observado que a área mínima por molécula e a elasticidade da monocamada na fase condensada (C) aumentam juntos com a porcentagem dos BCD. Na presença de BCD 180º as isotermas de potencial superficial (?V-A) sofrem uma expansão, no entanto, o valor máximo do potencial permanece nalterado. Isto indica que os BCD estimulam (antecipam) a orientação das moléculas de DPPC na interface ar-água e, consequentemente, a co-orientação das cabeças polares do DPPC, mas não contribuem no potencial superficial. Foi observado que a presença de NaCl na subfase aumenta o efeito dos BCD na formação da monocamada DPPC. Acreditamos que este efeito sinérgico é devido às interações mútuas dos ânions Cl- com a carga positiva do grupo trimetilamônio da cabeça polar do DPPC e das cargas positivas do BCD com a carga negativa do grupo fosfato do DPPC. As imagens obtidas pela microscopia de ângulo de Brewster mostram, em concordância com a análise das isotermas de pressão (?-A) e de potencial (?V- A), que a formação dos domínios, e conseqüentemente da monocamada, é antecipada na presença de BCD. Entretanto, a presença do BCD não altera o formato dos domínios, mas diminui seu tamanho. A análise realizada sobre os espectros de absorção óptica mostrou que os BCD podem formar agregados tipos H na monocamada e não foram observados agregados tipo J. Baseando-se na análise do efeito da estrutura dos BCD, na interação com a monocamada, e dos espectros de absorção propusemos dois modelos de interação dos BCD com a monocamada e acreditamos que o seguinte modelo é a melhor modelagem do sistema: - BCD se inseri na monocamada, paralelamente ao eixo da molécula de DPPC, interagindo tanto com a cauda hidrofóbica quanto com a cabeça polar. Entretanto, os resultados obtidos não permitem excluir completamente o segundo modelo proposto, no qual o BCD se localiza na parte polar da monocamada, perpendicular ao eixo da molécula de DPPC. / In this work the interaction of cyanine dyes with two chromophores with the DPPC phospholipid Langmuir monolayers was studied. Due to their high optical absorption in the region ? > 600 nm, high triplet state quantum yields, high photocytotoxicity and high affinity with cell structures the BCD are promising for application in photodynamic therapy. The study of the interaction of BCD with monolayers is important to clarify the structural effects on the monolayer interaction with other molecules as well as for application in photodynamic therapy and in other fields of technology, such as nanoelectronics, photonics, etc. The superficial pressure isotherms (?-A) demonstrate that BCD do interact with monolayers, the (?-A) isotherms being expanded when the BCD relative content increases. This interaction depends on the BCD structure and the subphase ionic strength, as well. The curves of the compressibility module (Cs-1 = -A (??/?A) of the monolayers were obtained from the (?-A) isotherms, which were used for detailed analysis of the DPPC monolayer formation in the BCD presence. The analysis demonstrated that the monolayer expanded liquid phase and the domain were formed earlier in the BCD presence than for pure DPPC. It was observed that both the minimum area per molecule and the condensed phase elasticity increased when the BCD relative content increased. In the presence of BCD 1800 the superficial potential isotherms (?V-A) were expanded, but the maximum potential value was unchanged. This indicates that BCD stimulated the DPPC molecule orientation on the air-water interphase and, consequently, the co-orientation of the DPPC polar heads, but did not contribute itself in the surface potential. It was observed that NaCl in the subphase increased the BCD effects on the DPPC monolayer formation. We suppose that this synergetic effect is due to the mutual interaction of Cl- anions with positive charges of the trimethylammonium group of the DPPC polar head and that of positive BCD charges with its phosphate group negative charges. Images obtained with the Brewster microscopy confirmed that BCD stimulated the domain and, consequently, the monolayer formation in accordance with the (?-A) and (?V-A) analysis. At the same time the BCD did not change the domain geometry, but reduced their sizes. The analysis of the BCD optical absorption spectra demonstrate that the BCD molecules in the monolayer form H aggregates and no J aggregates were observed. Basing on the analysis of the BCD structure effects on the monolayer formation we can propose two models of the BCD - monolayer interaction and we believe that the follow model is better: - the BCD molecule is inserted in the monolayer interior being parallel with the DPPC molecule axis and interacting with both hydrophobic and polar DPPC parts; However, our data are not sufficient to exclude completely the possibility for the BCD molecule to be localized just in the polar head monolayer part being perpendicular to the DPPC molecule axis.

Les travaux décrits dans cette thèse portent sur la synthèse ainsi que l’étude physico-chimique et photo-chimique de plusieurs séries de nitroxydes et d’alcoxyamines photosensibles fonctionnalisées par des chromophores de type benzophénone, fluorènone, anthraquinone, phényle, naphtyle et anthracényle. En particulier, nous avons focalisé notre effort sur l’introduction de ces chromophores sur un nitroxyde dérivé d’un noyau isoindoline connu pour sa stabilité photo-chimique. L’étude de la photo-dissociation des alcoxyamines préparées a ensuite été conduite par résonance paramagnétique électronique. Les résultats obtenus mettent en évidence deux nouvelles classes d’alcoxyamines photosensibles qui présentent une efficacité remarquable de photo-dissociation homolytique pour donner les radicaux nitroxyle et alkyle correspondant sous UV et irradiation de lumière visible. En effet, les alcoxyamines de type naphtyle et anthraquinone ont donné des rendements de dissociation homolytique quantitatifs sous irradiation UV et visible, et ce, quel que soit le fragment alkyle libéré (i.e. styryle, méthacrylyle, acrylyle). De plus, nous avons également montré que les nitroxydes portant les chromophores naphtyle et anthraquinone présentent une stabilité photochimique élevée. Ainsi, l’analyse de ces résultats suggère que les alcoxyamines dérivées de ces deux nitroxydes présentent toutes les caractéristiques requises pour être des candidats performants en photopolymérisation radicalaire contrôlée en présence de nitroxydes. / The work reported herein details the synthesis, as well as the photophysical and photochemical analysis, of novel unsubstituted benzophenone-, methoxy substituted benzophenone-, pyrrolidine substituted benzophenone-, fluorenone-, anthraquinone-, phenyl-, naphthyl- and anthracenyl-based photosensitive alkoxyamines for potential application in nitroxide-mediated photopolymerization.The high photochemical stability of the isoindoline class of nitroxide was exploited within the structural design. Fusion of the isoindoline motif into the examined chromophores facilitated efficient energy transfer between chromophore and alkoxyamine motifs, whilst exerting minimal influence on the photophysical properties of the investigated chromophores. Photochemical investigation of the examined alkoxyamines highlighted two new classes of photosensitive alkoxyamines which displayed highly desirable photo-dissociation efficiencies to afford nitroxide and alkyl radicals under UV and visible light irradiation. Specifically, styrenic, methacrylic and acrylic naphthyl-based alkoxyamines, as well as, styrenic and methacrylic anthraquinone-based alkoxyamines demonstrated near quantitative yields of photo-dissociation under UV and visible light irradiation respectively. The high yields of photo-dissociation obtained for the naphthyl- and anthraquinone-based systems, as well as the high photochemical stability of their corresponding nitroxides, indicate these new classes of photosensitive alkoxyamines are highly relevant candidates for further investigation within a photopolymerization context.

No description available.

L'objet de ce travail de thèse concerne la synthèse par réaction cascade pallado-catalysé d'une nouvelle famille de chromophores pentacycliques azotés dont les propriétés de fluorescence peuvent être modulées en fonction des groupements fonctionnels présents dans la molécule. Ces chromophores sont obtenus par réaction one-pot entre des acides 2-formyl boroniques et des 2,5-dihalopyridines. Le processus cascade est initié par un couplage de Suzuki suivi par deux cyclisations successives. La première se fait sur l'azote de la pyridine et la seconde se produit de façon régio-sélective sur le carbone adjacent à l'azote. Les structures cristallines et le calcul théorique DFT ont montré la régio et la stéréo-sélectivité de la réaction. De plus, des études préliminaires ont montré que ces composés polycycliques possèdent d'excellentes propriétés de fluorescence ainsi qu'une activité biologique qui devraient nous permettre d'étendre le champ d'application de ces nouveaux chromophores vers le domaine médical et l'électronique moléculaire / The aim of this work concerns the synthesis of a new family of aza-pentacyclic chromophore whose fluorescence properties can be modulated according to the functional groups present in the molecule. These chromophores were obtained through a cascade process between 2-formylbenzene boronic acid and 2,5-dihalopyridines. The cascade process is initiated by a palladium-catalyzed cross-coupling reaction and is followed by two successive nucleophilic cyclizations; the first cyclization performed on the pyridine nitrogen and the second occurred regioselectively on the adjacent carbon atom. This new cascade reaction allowed the formation of a pentacycle as a single regioisomer with four new bonds and two contiguous stereocenters with trans relationships. In addition, preliminary studies have shown that these polycyclic compounds have excellent fluorescence properties as well as biological properties that should enable us to extend the scope of these new chromophores to the medical field and molecular electronics

Os corantes ciânicos com dois cromóforos possuem características espectrais e energéticas vantajosas para aplicação em Terapia Fotodinâmica (TFD) do câncer. Entretanto, sua fotoatividade contra neoplasias não foi ainda estudada nem in vivo nem in vitro. Nesta tese apresentamos os resultados dos estudos in vitro dos mecanismos da fotocitotoxicidade dos corantes ciânicos com dois cromóforos (BCD) com ângulos entre os cromóforos = 1800, 1500 e 900 contra células neoplásicas, com a finalidade de avaliar a potencialidade da aplicação dos BCD como fotossensibilizadores (FS) em TFD. Os estudos foram realizados em comparação com o fotossensibilizador Photogem®,que já está sendo aplicado em TFD. Foram estudados o efeito fototóxico, a distribuição intracelular do BCD e a contribuição de apoptose e necrose na morte celular induzida por ele. Além disso, foi realizada a busca da formulação farmacêutica adequada para aplicação tópica do BCD180. Nos estudos da fotocitotoxicidade foram utilizadas as células neoplásicas de melanoma murino B16F10, melanoma humano C8161, adenocarcinoma de colo retal humano HT29, leucemia T humano (Jurkat) e leucemia mielóde aguda humana Hl-60. A citotoxicidade foi estudada em função da dose da irradiação, da concentração do FS e do tempo de incubação das células com FS. Todos os compostos testados apresentaram baixa citotoxicidade no escuro, quando sob irradiação com luz visível (? > 600 nm) sua citotoxicidade aumentou consideravelmente. Observamos que para todos os tipos de células neoplásicas a fotocitotoxicidade dos BCD, depois de atingir seu máximo na variação do tempo de incubação, é igual ou ultrapassa a fotocitotoxicidade do Photogem® nas mesmas condições experimentais. O estudo comparativo do BCD180 e dos BCD150 e BCD90 mostrou que nas mesmas condições experimentais os dois últimos possuem fotocitotoxicidade maior do que o BCD180. O conjunto dos resultados obtidos mostra que os BCD? podem ser considerados promissores FS para TFD do câncer. Os estudos através de microscopia de fluorescência da distribuição intracelular do BCD180 e dos marcadores fluorescentes das mitocôndrias Mitotracker GreenTM e Rodamina 123 e do núcleo 4\',6-diamidino-2-phenylindole (DAPI) mostraram que o BCD180 se localiza preferencialmente na região das mitocôndrias. Os mecanismos da morte celular induzida pelo BCD180 foram analisados através do estudo da morfologia das células Jurkat, liberação da fosfatidilserina, liberação do citocromo c, ativação da caspase-3 e do efeito na citotoxicidade do BCD180 da proteína Bcl-2 (inibidor do citocromo c). A análise mostrou que a apoptose é a principal responsável pela morte celular induzida pelo BCD180 no escuro, enquanto que, sob irradiação luminosa, tanto a apoptose quando a necrose contribuem para a morte celular, e a contribuição da necrose aumenta com o aumento da concentração do BCD180 e do tempo de pós-irradiação. A apoptose ocorre, provavelmente, pela via intrínseca ou mitocondrial. Além disso, foram realizados os testes de permeação cutânea do BCD180 utilizando várias formulações farmacológicas e foi determinado que a mistura de 10% de monoleína em propilenoglicol possui melhores características entre todas as formulações testadas. / Cyanine dyes with two chromophores possess vantage spectral and energetic characteristics for application in Photodynamic Therapy (PDT) of cancer. At the same time, their photoactivity against neoplasias was not yet studied neither in vivo, nor in vitro. In this thesis, we present the results of in vitro studies of photocytotoxicity mechanisms of cyanine dyes with two chromophores (BCD) with angles = 180,150 and 90 between chromophores against neoplasic cells, with the objective to evaluate BCD potentiality to be applied as photosensitizers (PS) to Photodynamic Therapy (PDT). The studies were realized in comparison with photosensitizer Photogem®, which is already applied to PDT. The BCD? phototoxic effect, their intracellular distribution and contribution of the apoptosis and necrosis in the cell death induced by BCD were studied. Besides, the search of adequate pharmaceutical formulation for BCD180 topic application was realized. The neoplasic cell lines of melanoma B16F10 in mice, human melanoma C8161, human colon adenocarcinoma HT29, human T-cell leukemia (Jurkat) and human leukemia Hl-60, were used in the study of photocytotoxicity, which was studied as a function of irradiation dose, PS concentration and incubation time of cells with PS. All tested compounds demonstrated low cytotoxicity in the darkness, while under irradiation by visible light (? > 600 nm) their cytotoxicity considerably increased. It was observed that for all types of neoplasic cells BCD photocytotoxicity under the same experimental conditions is equal or exceeds that of Photogem® when reaches the maximum with the incubation time variation. The comparative study of BCD180 with BCD150 and BCD90 demonstrated that under the same experimental conditions two latter compounds possess photocytotoxicity exceeding that of BCD180. A set of the results obtained demonstrates that BCD can be considered as promising PS for PDT of cancer. The study of intracellular distribution of BCD180, and of mitochondria and nucleus fluorescence selective probes Mitotracker GreenTM, Rhodamine 123 and 4\',6-diamidino-2-phenylindole (DAPI) show that BCD180 is mostly localized in the region of mitochondria. The mechanisms of the cell death induced by BCD180 were analyzed in the study of Jurkat cells morphology, phosphatidyl serine and cytochrome c liberation, caspase-3 activation, and by protein Bcl-2 (cytochrome c inhibitor) effect on BCD180 cytotoxicity. The analysis demonstrated that apoptosis is the main responsible for the cell death induced by BCD180 in darkness, while under light irradiation both apoptosis and necrosis contribute to the cell death, and necrosis contribution increases with BCD180 concentration and post-irradiation time.The apoptosis is probably realized by an intrinsic or mitochondrial way. Besides, the tests of BCD180 cutaneum permeation were realized using various pharmacological formulations. It was determined that among all formulations tested, the mixture of 10% of monoleine in propylene glycol possesses the best characteristics.

Les travaux effectués durant cette thèse ont eu pour objectif le développement de chromophores fonctionnels à base de sels de styrylpyrylium et styrylpyridinium. Les divers composés synthétisés ont montré une très grande flexibilité concernant leurs propriétés optiques, avec notamment des longueurs d’onde d’absorption et d’émission couvrant la quasi-totalité du spectre visible. Associée à la variabilité structurelle inhérente à ce type de chromophore, il est possible d’obtenir des composés aux propriétés modulables, et intégrables dans une large gamme d’applications.Ce manuscrit est constitué de trois parties principales. La première décrit la synthèse et les propriétés photophysiques de divers chromophores obtenus durant cette thèse. La seconde décrit l’approche théorique, utilisée pour faciliter la conception et l’analyse des composés étudiés. Finalement, la troisième partie décrit les applications pour lesquelles certaines variations de sels de styrylpyrylium et styrylpyridinium ont étés spécialement développés. / The work done during this thesis aimed to develop functional chromophores based on styrylpyrylium and styrylpyrylium salts. The compounds synthesized have shown a great flexibility regarding their optical properties, including maximum wavelength of absorption and emission covering almost the entire visible spectrum. Combined to their structural adaptability, it was possible to design various compounds compatible with a wide range of applications.This manuscript is composed of three main parts. The first part describes the synthesis and the photophysical properties of some chromophores obtained during this thesis. The second describes the theoretical approach, used to assist the design and the analysis of the studied compounds. Finally, the third part describes various applications for which some styrylpyrylium and styrylpyridinium salts have been specially designed.

<p> </p><p>The interaction between light and organometallic chromophores has been investigated theoretically in a strive for fast optical filters. The main emphasis is on two-photon absorption and excited state absorption as illustrated in the Jablonski diagram. We stress the need for relativistic calculations and have developed methods to address this issue. Furthermore, we present how quantum chemical calculations can be combined with Maxwell's equations in order to simulate propagation of laser pulses through a materials doped with chromophores with high two-photon absorption cross sections. Finally, we also discuss how fast agile filters using spin-transition materials can be modeled in order to accomplish theoretical material design.</p> / Report code: LIU-TEK-LIC-2006:55. On the day of the defence date the status on article III was Manuscript, article IV was Accepted and article V was Submitted.

The present thesis concerns aspects of the interaction ofmatter in gas, liquid and solid phases, with electromagneticradiation, ranging from the optical to the X-ray region. Overthe last decade the availability of ultrashort strong laserpulses as well as of high power synchrotron sources of tunableX-ray radiation has stimulated a rapid development of newexperimental techniques which makes it possible to analysedifferent physical, chemical and biological processes inunprecedented detail. All of this urges a concomitantdevelopment of adequate theoretical language and methodscombined with simulation techniques. The first part of the thesis addresses nonlinear propagationof strong optical pulses. This study is motivated by thebreakthrough in synthesis of novel organic materials possessingprespecified nonlinear optical properties and which has led toa multitude of potential applications such as, for example, 3Dimaging and data storage, optical limiting and photodynamiccancer therapy. In order to clarify the underlying physics, astrict solution has been derived of the density matrixequations of a material aiming at an explicit treatment of itsnonlinear polarization without addressing a conventional Taylorexpansion over field amplitudes. Such a formalism is developedfor many-level molecules, allowing to solve the coupledMaxwell's and density matrix equations for the propagation of afew interacting laser pulses through a nonlinear molecularmedium. The theory presented is capable to account formulti-photon processes of an arbitrary order and for differentsaturation effects. The theory is applied to simulations oftwo- and three-photon absorption as well as to upconvertedstimulated emission of organic molecules in solvents. The second part of the thesis is devoted to resonant X-rayRaman scattering from free molecules, solutions and polymerfilms. The temporal analysis of the spectral profiles isperformed using the technique of scattering duration whichallows to select physical processes with different time scales.The slowing-down/speeding-up of the scattering by frequencydetuning provides insight in the formation of the differentparts of the scattering profile like atomic and molecularbands, resonant and vertical scattering channels, anomalousenhancement of the Stokes doubling effect. The lifetimevibrational interference (LVI), playing a crucial role inresonant scattering, is found to strongly influence thedispersion of the Auger resonances of polymers in agreementwith experiment. An almost complete quenching of the scatteringcross section by LVI is observed for the N2molecule. It is found that the interferenceelimination of the scattering amplitude gives valuableinformation on molecular geometry. The electron Doppler effectis minutely studied making use of a wave packet technique. Thesimulations show an "interference burning" of a narrow hole onthe top of the Doppler broadened profile of the Auger spectraof molecular oxygen. For the SF6molecule the Auger Doppler effect is found to besensitive to the detuning due to the scattering anisotropy. Inall of these studies the temporal language was foundconstructive and enormously helpful for understanding theunderlying physical processes. Most theoretical predictionsmade have been verified by experiments.

<p>The present thesis concerns aspects of the interaction ofmatter in gas, liquid and solid phases, with electromagneticradiation, ranging from the optical to the X-ray region. Overthe last decade the availability of ultrashort strong laserpulses as well as of high power synchrotron sources of tunableX-ray radiation has stimulated a rapid development of newexperimental techniques which makes it possible to analysedifferent physical, chemical and biological processes inunprecedented detail. All of this urges a concomitantdevelopment of adequate theoretical language and methodscombined with simulation techniques.</p><p>The first part of the thesis addresses nonlinear propagationof strong optical pulses. This study is motivated by thebreakthrough in synthesis of novel organic materials possessingprespecified nonlinear optical properties and which has led toa multitude of potential applications such as, for example, 3Dimaging and data storage, optical limiting and photodynamiccancer therapy. In order to clarify the underlying physics, astrict solution has been derived of the density matrixequations of a material aiming at an explicit treatment of itsnonlinear polarization without addressing a conventional Taylorexpansion over field amplitudes. Such a formalism is developedfor many-level molecules, allowing to solve the coupledMaxwell's and density matrix equations for the propagation of afew interacting laser pulses through a nonlinear molecularmedium. The theory presented is capable to account formulti-photon processes of an arbitrary order and for differentsaturation effects. The theory is applied to simulations oftwo- and three-photon absorption as well as to upconvertedstimulated emission of organic molecules in solvents.</p><p>The second part of the thesis is devoted to resonant X-rayRaman scattering from free molecules, solutions and polymerfilms. The temporal analysis of the spectral profiles isperformed using the technique of scattering duration whichallows to select physical processes with different time scales.The slowing-down/speeding-up of the scattering by frequencydetuning provides insight in the formation of the differentparts of the scattering profile like atomic and molecularbands, resonant and vertical scattering channels, anomalousenhancement of the Stokes doubling effect. The lifetimevibrational interference (LVI), playing a crucial role inresonant scattering, is found to strongly influence thedispersion of the Auger resonances of polymers in agreementwith experiment. An almost complete quenching of the scatteringcross section by LVI is observed for the N₂molecule. It is found that the interferenceelimination of the scattering amplitude gives valuableinformation on molecular geometry. The electron Doppler effectis minutely studied making use of a wave packet technique. Thesimulations show an "interference burning" of a narrow hole onthe top of the Doppler broadened profile of the Auger spectraof molecular oxygen. For the SF₆molecule the Auger Doppler effect is found to besensitive to the detuning due to the scattering anisotropy. Inall of these studies the temporal language was foundconstructive and enormously helpful for understanding theunderlying physical processes. Most theoretical predictionsmade have been verified by experiments.</p>

Photodynamic therapy (PDT) is an alternative treatment of cancer requiring the use of chromophore molecules (photosensitizers), which can induce cell death after light excitation. Gold nanoparticles (AuNP), exhibiting localized Surface Plasmon Resonance, can enhance the photophysical response of chromophores located in their vicinity, and thus improve their therapeutic action. Moreover, the use of highly localized two-photon chromophores (photosensitizers and fluorophores), capable to undergo a localized excitation by light in the Near InfraRed region, should increase the penetration depth into tissues, thus improve the treatment efficiency (by PDT) and the imaging (by fluorescence microscopy) of cancer tissues.In this work, we describe the elaboration of water-soluble hybrid nano-objects for PDT and fluorescence bioimaging applications, composed of two-photon chromophore-polymer conjugates grafted onto gold nanoparticles. In order to obtain these nano-objects we follow a multistep strategy: i) the synthesis of a well-defined water-soluble chromophore-polymer conjugates; ii) the end-group oriented grafting of chromophore-polymer conjugates onto 20 nm AuNP. The coupling of hydrophobic two-photon chromophores on linear water-soluble copolymer chains (poly(N-acryloylmorpholine-co-N-acryloxysuccinimide)), obtained by controlled/living RAFT polymerization, resulted in well-defined water-soluble chromophore-polymer conjugates, with different polymer lengths (2 000 g.mol-1 < Mn < 37 000 g.mol-1) and architectures (random or block), and a controlled number of chromophores per chain (varying between 1 and 21). Their grafting onto 20 nm AuNP gave water-soluble hybrid nano-objects with high grafting densities (~0.5 chains/nm²). The role of the polymer chain being to tune the distance between chromophores and AuNP surface, we have evidenced the increase in the polymer corona thickness of grafted AuNP (estimated by TEM) with the increasing polymer Mn, corroborating with the corresponding distance-dependent fluorescence properties of those. Finally, the in cellulo biological properties of two-photon chromophore-polymer conjugates, before and after grafting onto AuNP, have been investigated, highlighting their potential for two-photon bioimaging and PDT applications.