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Highlights: [•] Alkaline phosphatase was adsorbed on “polydopamine” films. [•] The enzymatic activity was evaluated as a function of storage time. [•] “Polydopamine” films display some phosphatase like activity. [ABSTRACT FROM AUTHOR]

Objective: We investigated the incidence and injury patterns of acute parachuting injuries evaluated at a level II military facility during a 5-year period to compile medical information that may assist in improving the safety of parachuting. Methods: A retrospective chart review of all parachuting injuries that presented to the Madigan Army Medical Center emergency department in Tacoma, Washington, during a 5-year period from February 2005 to June 2011. Results: A total 110 patient charts met inclusion criteria. Lower extremity injuries made up 65% of total injuries, followed by 22% head injuries, 22% neck or back injuries, and 19% upper extremity injuries. One patient died in the emergency department of head injuries, and 1 patient was transferred for an open-book pelvic fracture. The most common phase of the jump in which to sustain injury was at landing. A total of 15 patients were admitted to the hospital. It is of note that some patients had combined injuries. The mechanism of injury documented in 96 of 110 (87%) patients and 10 of 15 (66%) admitted patients was a difficult landing. Conclusions: The rate of injury for each area of the body is within previously reported rates, with lower extremity injuries making up the largest category and leading to the majority of admissions. The most common time to sustain an injury was during landing, which represented a majority of both emergency room visits and hospitalizations. [ABSTRACT FROM AUTHOR]

Highlights: [•] Proteins allow to control the size of dopamine-eumelanin particles. [•] The kinetics of dopamine-eumelanin formation is also accelerated in the presence of those proteins. [•] Fibroblasts keep their viability in the presence of HAS dopamine-eumelanin nanoparticles. [Copyright &y& Elsevier]

Highlights: [•] The zeta potential of (PAH-polyoxometalate) n films is measured as a function of the ionic strength. [•] The zeta potential is stable as a function of time when the ionic strength is higher than 50mM. [•] At smaller ionic strengths, the zeta potential decreases without desorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electrodeposition of pyrocatechol is compared with that of pyrogallol. • In case of CV deposition pyrogallol yields impermeable films of higher impedance. • In case of chronoamperometry, pyrocatechol yields impermeable films of higher impedance. The electrodeposition of films from redox active molecules has become an attractive surface functionalization method owing to its surface selectivity and one pot nature. Many investigations focused on the deposition mechanism of particular molecules such as aniline or thiophene. Fewer studies focused on derivatives of phenols and very few were aimed to compare the electrochemical properties of the obtained films when the chemical nature of the phenol derivative is changed, for instance upon the addition of an hydroxyl group on the benzene cycle, or when the nature of the deposition method is changed, namely variable (cyclic voltammetry, CV) or constant potential (chronoameprometry, CA). This investigation compares the influence of the film deposition method on the electrochemical properties of deposits made from pyrogallol or pyrocatechol on amorphous carbon electrodes. It is shown that CA is more efficient for the deposition of pyrocatechol based films than for pyrogallol based films. On the other hand, a lower number of CV cycles is required to obtained films impermeable to hexacyanoferrate anions in the case of pyrogallol compared to pyrocatechol. [ABSTRACT FROM AUTHOR]

Highlights: [•] Step-by-step assembly of dopamine-eumelanin and metal cations (Cu2+, Fe3+, La3+) is possible. [•] The coatings made from trivalent cations growth faster than those made from Cu2+. [•] Fe3+ does not undergo a change in its redox state upon incorporation in the coatings. [ABSTRACT FROM AUTHOR]

Polyoxometalates (POMs) are inorganic metal oxoanions with a negative charge, stabilized in the solid state by the corresponding number of countercations and possibly protons. In aqueous solution, the dissociation of all ion pairs is not necessarily quantitative because this would result in strong electrostatic repulsion among the polyanions. In the present communication, we show that the effective charge of the donut-shaped 30-tungsto-5-phosphate [NaPWO] (PW) is close to its 'structural charge' of 14 elementary negative charges in the presence of linear polyamines, namely, poly(allylamine hydrobromide) and poly( l-lysine hydrobromide) in a 10-mM NaBr electrolyte. When phase separation occurs, leading to a precipitate (rich in polyanion) and an almost clear supernatant, the charge ratio of the number of moles of cationic groups to polyanion is close to 14, showing that the effective charge in a solution of PW is indeed equal to −14 e in the presence of polycations. [ABSTRACT FROM AUTHOR]

Surface coatings obtained by a step-by-step(SBS) deposition process of polymers carrying mutually complementarymoieties (like polycations and polyanions) allow for a versatile multifunctionalizationof a vast kind of materials. However the SBS deposition process canbe extremely time-consuming when it is performed by alternativelydipping the substrates in the solutions carrying the interacting species.There is hence an important need to obtain coatings of similar compositionas those obtained in the SBS manner but in a “one pot”manner. Here we show that the sedimentation of stoichiometric polyelectrolytecomplexes can lead to a homogeneous coating. This is possible if thepolylectrolyte complexes display a high internal mobility. The filmgrowth rate is then in direct relation with the sedimentation rateof its constituting complexes. On the other hand when the interactionsbetween the oppositely charged polyelectrolytes are too strong, theobtained coating is neither continuous nor homogeneous. [ABSTRACT FROM AUTHOR]

Polyelectrolyte multilayer (PEM) films present a versatile surface functionalization method allowing to address many applications. These coatings suffer; however, from weak mechanical properties this problem can be addressed by the regular incorporation of clays in the layering process. To allow for an even better control of a whole set of film properties, among them their thermal stability, their stability in water, and their impermeability to anions, we postmodify (PAH-MMT) films with polydopamine, by putting the pristine PEM films in contact with an oxygenated dopamine solution. This straightforward treatment allows to totally suppress the diffusion of hexacyanoferrate anions in the films and affects significantly its mechanical properties even, if the distribution of polydopamine through the film thickness is not yet known. [ABSTRACT FROM AUTHOR]

Abstract: The formation of “polydopamine” thin films becomes a popular method to confer multifunctionality to solid–liquid interfaces through the available catechol groups of such films. The mechanism of film formation is, however, not well elucidated, and most investigators use the protocol developed by Messersmith et al. (H. Lee, S.M. Dellatore, W.M. Miller, P.B. Messersmith, Science 318 (2007) 426.) using a dopamine solution at a constant concentration of 2gL−1 in the presence of Tris(hydroxymethyl aminomethane) at pH 8.5. A particular finding of this initial study was that the film thickness reaches a constant value (almost substrate independent) of about 40nm. Herein, we investigate the change in the polydopamine film thickness, morphology, surface energy and electrochemical properties as a function of the concentration of the dopamine solution put in the presence of silicon substrates. As a surprising finding, we observe a constant increase in the maximal film thickness with an increase in the dopamine solution between 0.1 and 5gL−1. The surface morphology is also markedly affected by the concentration of the dopamine solution, whereas the different components of the surface energy stay unaffected by the dopamine solution concentration. In addition, electrochemical impedance spectroscopy shows that the higher the initial dopamine concentration, the more rapidly compact and impermeable films are formed. Finally, we propose a model for the deposition of polydopamine films taking all our findings into account. This model relies on a rate equation taking into account both attractive and repulsive interactions between small polydopamine aggregates on the surface and in solution. [Copyright &y& Elsevier]

The lateral diffusion of a protein (human serum albuminlabeledwith fluorescein isothiocyanate) within a highly hydrated polyelectrolytefilm is studied. The film is built up with poly(l-lysine)as polycation and hyaluronate as polyanion. Fluorescence recoveryafter photobleaching is used to evaluate the mobility of the labeledprotein. Spatial Fourier transformation is applied to the fluorescenceintensity recorded at various times after bleaching of a narrow rectangulararea within an image representative of the film. This approach necessitatesno hypothesis on the intensity distribution at the end of the bleachingprovided that the bleach has not appreciably changed the concentrationratios of the different diffusing species. Furthermore, under thehypothesis that molecules move according to Fick’s law, werepresent the Fourier transform by a weighted sum of exponentialseach containing another diffusion coefficient and evaluate the proportionattached to each term of this sequence using the simulated annealingmethod. A criterion, combining goodness-of-fit and the entropy characterizingthe diffusion coefficient spectrum, is proposed to avoid overinterpretationof the experimental data. The optimum spectrum of the diffusion coefficientis then extracted from the time evolution of the light intensity atvarious albumin concentrations within the films. It appears that themobility, quantified by the amount of tracer molecules having a diffusioncoefficient smaller than, e.g., 0.1 μm2/s, undergoesa transition between 20 and 2000 μg/mL of internal concentration.This suggests that the mutual interactions of the albumin moleculesand the interactions between fluorescently labeled albumin and thefilm network become increasingly important in the reduction of thealbumin mobility as the albumin concentration increases. [ABSTRACT FROM AUTHOR]

Abstract: The deposition of polyelectrolyte multilayer films (PEMs) appears more and more as a versatile tool to functionalize a broad range of materials with coatings having controlled thicknesses and properties. To increase the control over the properties of such coatings, a good knowledge of their deposition mechanism is required. Since Cohen Stuart et al. (Langmuir 18 (2002) 5607–5612) showed that the adsorption of one polyelectrolyte could induce desorption of polyelectrolyte complexes instead of regular deposition, more and more findings highlight peculiarities in the deposition of such films. Herein we demonstrate that the association of sodium polyphosphate (PSP) as the polyanion and either poly(-L-lysine hydrobromide) (PLL) or poly(allylamine chloride) (PAH) as the polycations may lead to non-monotonous film deposition as a function of time. Complementary, films containing PSP and PLL can be obtained from a (PLL–HA) n template films after the exchange of HA (hyaluronic acid) from the sacrificial template by PSP from the solution. This exchange is accompanied by pronounced film erosion. However, when starting from a (PAH–HA) n template, the film erosion and exchange due to the contact with PSP is by far less pronounced, nevertheless the film morphology changes. These findings show that the nature of the polycation used to deposit the PEM film may have a profound influence of the film’s response to a competing polyanion. [Copyright &y& Elsevier]

Abstract: Dopamine–melanin films produced through the oxidation of dopamine in the presence of oxygen as an oxidant allow to reduce silver ions onto silver particles as already described in the paper by Lee et al. (H. Lee, S.M. Dellatore, W.M. Miller, P.B. Messersmith, Science 318 (2007) 426.). This reduction process has to occur through the oxidation of moieties present in the melanin film. This investigation shows that the free radicals present in the pseudomelanin film, quantified by means of electron spin resonance spectroscopy (ESR) for the first time, are not used in the transformation of Ag+ cations to deposit silver. The ESR signal is hardly affected by the deposition of silver particles. On the other hand, X-ray photoelectron spectroscopy shows a small increase in the density of quinone groups and a small decrease of catechol groups on the surface of the film during the deposition of silver. This suggests that the deposited pseudomelanin films contain a significant fraction of catechol groups able to trigger reduction processes of metallic cations. These silver nanoparticles remain adherent to the melanin films and allow for a quantitative killing of Escherichia coli over a broad range of bacterial dilutions. However, the presence of the bacteria induces a release of the nanoparticles. The pseudomelanin films cannot be reused again for a silver ion reduction step. Nevertheless, the easy preparation of the pseudomelanin–silver composite and its effective one shot bacterial killing activity renders the strategy presented in this paper attractive. Some fundamental questions about redox process allowed by the pseudomelanin films will also be asked. [Copyright &y& Elsevier]

The formation of bacterial biofilms on the surface of implanted materials is a critical factor that may lead to chronic microbial infection and tissue necrosis. In the present study we analysed the stability of polyelectrolyte multilayer (ML) films on suture materials and the antibacterial effect obtained with chlorhexidine (CHX)-functionalized films built on different types of suture materials such as silk, polyester and copolymer of glycolide and l-lactide. The comparison of Escherichia coli culture on glass coverslips and glass coverslips with ML and CHX showed at 24 h an inhibition of the bacterial relative luminescence (40.68%, P < 0.5) and at 48 h (99.46%, P < 0.001). In another way, simple soaking of suture material overnight in CHX digluconate 20% without polyelectrolyte films did not at all protect sutures from bacterial colonization but CHX-functionalized polyelectrolyte films, made from poly- l-glutamic acid and poly- l-lysine, inhibited Escherichia coli proliferation. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the different molecular recognition systems used for inducing adhesion, fusion of vesicles as well as their physical properties. A third part concerns the control of the release of vesicles at the solid interface thanks to an optimized polyelectrolyte coating. Various chemical strategies based on the incorporation of recognition lipids are presented and compared to induce and control the interaction between membranes. The kinetics effects in the adhesion and fusion processes are demonstrated by complementary techniques such as the micropipettes, fluorimetry and reflexion interference contrast microscopy. [Copyright &y& Elsevier]

Abstract: In this review we summarize novel aspects of the hydration and internal properties of polyelectrolyte multilayers formed by layer-by-layer assembly. Reflectivity techniques monitor the water content and swelling behavior, while spin relaxation monitors water mobility. Odd–even effects in dependence on the number of layers are discussed in terms of an influence of the terminating layer. Other novel methodological approaches like X-ray microscopy or NMR cryoporometry address the water content in hollow capsules, and the water pore size distribution, respectively. Multilayer material properties are relevant for different applications. As a novel concept, dielectric properties are monitored in a field effect transistor device. Ion mobility and redox processes in multilayers are revealed by the electrochemical properties. Mechanical properties of multilayers, studied by colloidal probe atomic force microscopy depend on the conformation of the polymers involved. [Copyright &y& Elsevier]

The understanding of the role of biological macromolecules in the nucleation of calcium carbonates and calcium phosphates is of primary importance for the development of biomimetic surfaces able to mimic the proteins used by living organisms to produce such composite materials. In this study we show how polyelectrolyte multilayers made from poly-l-lysine (PLL) as the polycation and from a mixture of two polyanions, poly-l-glutamic acid (PGA) and poly-l-aspartic acid (Pasp), at different ratios are able to affect the duration of the lag time preceding crystal growth at constant supersaturation. These polyelectrolyte multilayers appear as interesting candidates for biomimetic surfaces, since they display a content of β-sheets that can be controlled by changing the PGA proportion in the polyanion mixture. The duration of the lag times preceding fast crystal growth is measured in situ with three complementary techniques, namely quartz crystal microbalance with dissipation (QCM-D), optical waveguide lightmode spectroscopy (OWLS), and infrared spectroscopy in the attenuated total reflection mode (ATR-FTIR). The three techniques lead to comparable results, and ATR-FTIR spectroscopy allows us to demonstrate that the growing inorganic particles are calcium phosphates. The obtained mineral is most probably octacalcium phosphate or poorly crystalline hydroxyapatite, whatever the PGA content of the multilayer film. However, the duration of the lag time as well as the morphology of the obtained particles cannot be simply correlated with the β sheet content of the multilayer film. In this study we show how polyelectrolyte multilayers made from poly-l-lysine (PLL) as the polycation and from a mixture of two polyanions, poly-l-glutamic acid (PGA) and poly-l-aspartic acid (Pasp), at different ratios are able to affect the duration of the lag time preceding crystal growth at constant supersaturation. These polyelectrolyte multilayers appear as interesting candidates for biomimetic surfaces, since they display a content of β-sheets that can be controlled by changing the PGA proportion in the polyanion mixture. [ABSTRACT FROM AUTHOR]

The adsorption and desorption kinetics of six polypeptides, denoted by 1, 2, 3A, 3B, 4 and bee venom melittin, close in molecular weight but differing in their apparent charge state and hydrophobicity are investigated at a given bulk concentration (10−6 M) by means of optical waveguide light mode spectroscopy at an Si0.8Ti0.2O2–aqueous solution interface. At pH 8.0 and a salt concentration of 0.01 M, it is found that four of these polypeptides, 1, 2, 4 and melittin display quasi identical adsorption kinetics and differ only significantly with respect to their desorption kinetics. These observations could be rationalized by the calculation of their charge state in the framework of the Linderstro¨m-Lang model: in contrast with predictions based on their amino acid sequence, all these molecules display only a very small charge due to pKa modifications in this low ionic strength medium. In marked contrast to the four other polypeptides, the molecules 3A and 3B, identical in their amino acid composition but differing in the localization of four amino acids (through two point mutations), display smaller adsorption rates when put in contact with the sorbent. Moreover, their desorption kinetics could be fitted by means of only one exponential decay function whereas two exponentials where necessary for the first class of polypeptides. No evident reason is found to explain this peculiar adsorption behavior since 3A and 3B display the same average (calculated) charge state and hydrophobicity as the other investigated molecules. The polypeptides 1, 2, 3A, 3B display an adsorption hysteresis: their desorption rate constant depends markedly on the contact time between the polypeptide solution and the sorbent. In that sense, the interfacial behavior of these molecules is quite similar to that of large globular proteins. [Copyright &y& Elsevier]

This study investigated the antibacterial activity, bond strength to dentin (SBS), and ultra-morphology of the polymer–dentin interface of experimental adhesive systems doped with pyrogallol (PY), which is a ubiquitous phenolic moiety that is present in flavonoids and polyphenols. A universal adhesive containing 4-META and 10-MDP was used in this study. PY behaves as an antioxidant and anti-cancerogenic agent and it was incorporated into the adhesive at different concentrations (0.5 and 1 wt.%). The antibacterial activity and SBS were analyzed and the results were statistically analyzed. The ultra-morphology of the polymer–dentin interface was assessed using scanning electron microscopy (SEM). At 24 h, a lower antibacterial activity was observed for the control adhesive compared to those with 0.5% and 1% PY. No difference was seen in SBS between the three groups at 24 h. After 6 months, the SBS of the 0.5% PY adhesive was significantly lower than the other tested adhesives. The specimens created with 1% PY adhesive presented a higher bond strength at six months compared with that found at 24 h. No morphological differences were found at the polymer–dentin interfaces of the tested adhesives. Pyrogallol may be incorporated into modern universal adhesive systems to preserve the polymer–dentin bonding interface and confer a certain degree of antibacterial activity. [ABSTRACT FROM AUTHOR]

• The reaction of aminomalononitrile (AMN) at pH = 8.6 allows to produce coatings displaying redox activity. • This redox activity affords antioxidant properties to the AMN based films. • Those antioxydant properties depend on the film thickness and morphology. Conformal films obtained through polymerization of aminomalononitrile in solution at pH = 8.6 display an irreversible electrochemical oxidation current and a thickness/ morphology dependant antioxidant activity as measured by the quenching of 2,2-diphenyl-1-picrylhydrazyl. These findings illustrate that materials issued from molecules suspected to have played an important role in prebiotic chemical process offer application potentials in biomaterials science. [ABSTRACT FROM AUTHOR]

In recent years major advances in surface chemistry and surface functionalization have been performed through the development, most often inspired by living organisms, of versatile methodologies. Among those, the contact of substrates with aminomalononitrile (AMN) containing solutions at pH = 8.5 allows a conformal coating to be deposited on the surface of all known classes of material. Since AMN is a molecule probably formed in the early atmosphere of our planet and since HCN-based compounds have been detected on many comets and Titan (Saturn's largest moon) it is likely that such molecules will open a large avenue in surface functionalization mostly for bio-applications. This mini review describes the state of the art of AMN-based coatings from their deposition kinetics, composition, chemical reactivity, hypothetical structure to their first applications as biomaterials. Finally, the AMN-based versatile coatings are compared to other kinds of versatile coating based on catecholamines and polyphenols. [ABSTRACT FROM AUTHOR]

The tyrosinase-catalyzed oxidation of tyramine, leading to the deposition of pseudo-polydopamine (ψ-PDA) thin films, is disclosed herein as a superior technology for surface functionalization and coating at a neutral pH and at a low substrate concentration, compared to the standard autoxidative PDA coating protocols. Smooth ψ-PDA thin films of variable thickness up to 87 nm were obtained from 1 mM tyramine by varying tyrosinase concentrations (5–100 U/mL). Compared to the PDA films obtained by the similar enzymatic oxidation of 1 mM dopamine with tyrosinase (T-PDA), ψ-PDA displayed slower deposition kinetics, lower water contact angles in the range of 11°–28°, denoting higher hydrophilicity but similar UV-vis absorption profiles, as well as electrochemical properties and antioxidant activity. MALDI-MS analysis indicated for ψ-PDA a well defined pattern of peaks compatible with dopamine tetrameric structures degraded to a variable extent. The exposure to a tyramine solution of tyrosinase-loaded alginate spheres, or films deposited on glass or polyethylene, resulted in a rapid gel-confined ψ-PDA formation with no leakage or darkening of the solution, allowing the complete recovery and re-utilization of the unreacted tyramine. In contrast, an abundant PDA precipitation outside the gel was observed with dopamine under the same conditions. The ψ-PDA deposition by tyrosinase-catalyzed tyramine oxidation is thus proposed as a controllable and low-waste technology for selective surface functionalization and coating or for clean eumelanin particle production. [ABSTRACT FROM AUTHOR]

• Close similarity between polydopamine and eumelanin. • Several templating agents allow to obtain polydopamine based nanomaterials. • Biomimetic approaches appear the most successful. • Description of these nanomaterials as therapeutic agents and sensing materials. The mussel inspired chemistry of dopamine leading to versatile coatings on the surface of all kinds of materials in a one pot process was considered as the unique aspect of catecholamine for a long time. Only recently, research has been undertaken to valorize the simultaneous oxidation and colloid formation in dopamine solutions in the presence of an oxidant. This mini review summarizes the synthesis methods allowing to get controlled nanomaterials, either nanoparticles, hollow capsules or nanotubes and even chiral nanomaterials from dopamine solutions. Finally the applications of those nanomaterials will be described. [ABSTRACT FROM AUTHOR]

Polyphenols like tannic acid, and others, adsorb spontaneously to the surface of a vast repertoire of materials to coat them with a conformal and functional thin film. Since polyphenols can be oxidized, their deposition can also be controlled at the surface of conductive materials. Since the oxidized form of polyphenols contains reactive quinone groups it could be of interest to electropolymerize them in the presence of nucleophiles, like polyamines to obtain composite coatings with properties different from those displayed by a coating obtained from the polyphenol alone. However in conditions where polyamines are reactive and unprotonated, polyphenols undergo spontaneous, non controlled oxidation. In this article, the electropolymerization of tannic acid (TA) by means of cyclic voltammetry is performed at pH = 5.0. The obtained TA based coatings are compared to those obtained from blends with poly(allylamine hydrochloride) (PAH) as a primary polyamine and with poly(diallyldimethyl ammonium chloride) (PDADMAC) containing quaternary ammonium groups. In these conditions, the polyamines form complexes with TA. It will be shown by means of electrochemical impedance spectroscopy, that the higher the PAH concentration in the blend, the higher is the pseudocapacitance of the film. This finding is explained by the incorporation of positively charged PAH or PDADMAC into the film during the oxidation of TA and by the increase in film roughness/porosity in the presence of the polycation. [ABSTRACT FROM AUTHOR]

Astrochemistry and astrobiology, the fascinating disciplines that strive to unravel the origin of life, have opened unprecedented and unpredicted vistas into exotic compounds as well as extreme or complex reaction conditions of potential relevance for a broad variety of applications. Representative, and so far little explored sources of inspiration include complex organic systems, such as polycyclic aromatic hydrocarbons (PAHs) and their derivatives; hydrogen cyanide (HCN) and formamide (HCONH2) oligomers and polymers, like aminomalononitrile (AMN)-derived species; and exotic processes, such as solid-state photoreactions on mineral surfaces, phosphorylation by minerals, cold ice irradiation and proton bombardment, and thermal transformations in fumaroles. In addition, meteorites and minerals like forsterite, which dominate dust chemistry in the interstellar medium, may open new avenues for the discovery of innovative catalytic processes and unconventional methodologies. The aim of this review was to offer concise and inspiring, rather than comprehensive, examples of astrochemistry-related materials and systems that may be of relevance in areas such as surface functionalization, nanostructures, and hybrid material design, and for innovative technological solutions. The potential of computational methods to predict new properties from spectroscopic data and to assess plausible reaction pathways on both kinetic and thermodynamic grounds has also been highlighted. [ABSTRACT FROM AUTHOR]

Polydopamine can form biocompatible particles that convert light into heat. Recently, a protocol has been optimized to synthesize polydopamine/protein hybrid nanoparticles that retain the biological function of proteins, and combine it with the stimuli-induced heat generation of polydopamine. We have utilized this novel system to form polydopamine particles, containing transferrin (PDA/Tf). Mouse melanoma cells, which strongly express the transferrin receptor, were exposed to PDA/Tf nanoparticles (NPs) and, subsequently, were irradiated with a UV laser. The cell death rate was monitored in real-time. When irradiated, the melanoma cells exposed to PDA/Tf NPs underwent apoptosis, faster than the control cells, pointing towards the ability of PDA/Tf to mediate UV-light-induced cell death. The system was also validated in an organotypic, 3D-printed tumor spheroid model, comprising mouse melanoma cells, and the exposure and subsequent irradiation with UV-light, yielded similar results to the 2D cell culture. The process of apoptosis was found to be targeted and mediated by the lysosomal membrane permeabilization. Therefore, the herein presented polydopamine/protein NPs constitute a versatile and stable system for cancer cell-targeting and photothermal apoptosis induction. [ABSTRACT FROM AUTHOR]