Every holiday season, I get an influx of DMs, tweets, texts and messages from followers, friends and family asking for my photo gear recommendations. This year, rather than putting together a list of all the high-tech cameras and lenses that come with high-price tags to match – I wanted share some affordable add-ons that thrifty photographers should have in their arsenal. As I like to say, the best camera is the one you have with you and most of the time that’s the one in your pocket ????  If you are looking for gift ideas for the photographer on your list these are my go-tos under $100(ish).   Moment Lens  These pocket size lenses will transform your mobile device into a lightweight DSLR. With a variety of lenses from fisheye to macro, Moment add-ons are durable, easy-to-use and have incredible clarity. Compatible with almost every smartphone, these compact lens take the camera in your pocket up a notch.          Shure Mic Shure has transformed mobile audio with its line of mobile mics. Regardless of your price point, the audio company creates options that will take your sound from distorted to crystal clear. As a photographer and podcaster […]

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Photography Life has just contributed to the selection of online courses that you can take for free. While their premim courses are normally paid $150 per course, you can now access them free of charge. The founders have released them on YouTube, available for everyone to watch. The Photography Life team came to the decision […]

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Have you noticed extra-long and weirdly stretched images on your Instagram feed? It looks like some kind of a glitch has appeared, allowing users to post images like this to their followers. Of course, some Instagrammers have made the use of it to draw attention, and if you want to have some fun (or annoy […]

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With the coronavirus pandemic, many folks switched to working online. Things like teaching, business meetings and other face-to-face activities have been replaced with video calls. Home has become both home and workplace, and admit it: your wardrobe totally reflects this. Creative duo The Workmans shows this “fashion crossover” in their latest photo series #COVIDwear. The […]

The post #COVIDwear: a hilarious photo series showing quarantine fashion of remote workers appeared first on DIY Photography.

Hypertension is a potentially unsafe health ailment, which can be indicated directly from the Blood pressure (BP). Hypertension always leads to other health complications. Continuous monitoring of BP is very important; however, cuff-based BP measurements are discrete and uncomfortable to the user. To address this need, a cuff-less, continuous and a non-invasive BP measurement system is proposed using Photoplethysmogram (PPG) signal and demographic features using machine learning (ML) algorithms. PPG signals were acquired from 219 subjects, which undergo pre-processing and feature extraction steps. Time, frequency and time-frequency domain features were extracted from the PPG and their derivative signals. Feature selection techniques were used to reduce the computational complexity and to decrease the chance of over-fitting the ML algorithms. The features were then used to train and evaluate ML algorithms. The best regression models were selected for Systolic BP (SBP) and Diastolic BP (DBP) estimation individually. Gaussian Process Regression (GPR) along with ReliefF feature selection algorithm outperforms other algorithms in estimating SBP and DBP with a root-mean-square error (RMSE) of 6.74 and 3.59 respectively. This ML model can be implemented in hardware systems to continuously monitor BP and avoid any critical health conditions due to sudden changes.

At around 5:30 pm on Thursday, there were two camps of people set up in Coeur d'Alene Park in Browne's Addition.…

The invention relates 6-acyl-(6H)-dibenz[c,e][1,2]oxaphosphorin-6-oxides of the formula ##STR1## wherein each of R1, R2 and R3 may be present one or more times and R1, R2 and R3 represent halogen having an atomic number of from 9 to 35, alkyl or alkoxy each having from 1 to 6 carbon atoms and wherein Ar represents an aromatic hydrocarbon group having from 6 to 10 carbon atoms.The invention further relates to a process for the preparation of the afore-mentioned compounds and polymerizable compositions containing them as an essential ingredient as a photo-initiator. Finally the invention relates to 6-alkoxy-(6H)-dibenz[c,e][1,2]oxaphosphorin of the formula II ##STR2## wherein each of R1 and R2 may be present once or more times and R1 and R2 represent halogen having an atomic number of from 9 to 35, alkyl or alkoxy each having from 1 to 6 carbon atoms, at least one R1 being, however, halogen and wherein R4 represents alkyl having from 1 to 6 carbon atoms.

A metal complex having a β-diketonate represented by the following formula (1): wherein M represents a metal atom of the VIII group, R1, R2 and R3 represent a group or an atom selected from the group consisting of an alkyl group, an aryl group, a hydroxyl group, an amino group, an alkoxy group, a hydrogen atom and a halogen atom; X−1 represents an ion selected from a halogen, nitric acid, sulfonic acid, fluoroboric acid, fluorophosphoric acid, or perchloric acid ion; L1 or L2 represents a 2,2'-bipyridine or 1,10-phenanthroline group where these groups may be substituted with a group or an atom selected from an alkyl group, a carboxyl group, a sulfonic acid group, a phosphonic acid group, a hydroxyl group, an amino group, a hydrogen atom and a halogen atom. A photoelectric conversion element and a photochemical cell using the above-mentioned metal complex.

A photovoltaic cell, for example a thin-film photovoltaic cell, having a substrate glass made of aluminosilicate glass, has a glass composition which has SiO2 and Al2O3 as well as the alkali metal oxide Na2O and the alkaline earth oxides CaO, MgO, and BaO, and optionally further components. The glass composition includes 10 to 16 wt.-% Na2O, >0 to 1 to 10 wt.-% BaO, and the ratio of CaO:MgO is in the range of 0.5 to 1.7. The aluminosilicate glass used is crystallization stable because of the selected quotient of CaO/MgO and has a transformation temperature >580° C. and a processing temperature

Disclosed is a resin precursor composition including a bifunctional (meth)acrylate containing a fluorine atom, a bifunctional (meth)acrylate having a fluorene structure, and a photopolymerization initiator, the resin precursor composition in which the formation of precipitates during its storage is suppressed; and a resin obtained from the same. Specifically disclosed is a resin precursor composition that contains a bifunctional fluorine-containing (meth)acrylate (component A); a (meth)acrylate having a fluorene structure (component B); and a photopolymerization initiator (component C), wherein the component B includes a bifunctional (meth)acrylate having a fluorene structure (b-1) and a monofunctional (meth)acrylate having a fluorene structure (b-2) at a molar ratio (b-1):(b-2) of 90:10 to 70:30.

The invention provides a method for the manufacture of a catheter comprising a hydrophilic gel. The method comprising the steps of combining a polymeric photoinitiator of the general formula (I): R1(A1)r-(R2(A2)m-O)o—(R3(A3)n-O)p—R4(A4)s (I) with one or more gel-forming polymers and/or gel-forming monomers to form a matrix composition, curing the matrix composition by exposing it to UV radiation, exposing the matrix composition to a swelling medium and incorporating the hydrophilic gel into a catheter. The invention also provides autocuring of the polymeric photoinitiator (I) to provide a gel precursor, a hydrophilic gel and a catheter comprising or coated with the hydrophilic gel of the invention.

Provided is a photosensitive composition which can be cured with low energy consumption, even when a substance (such as a colorant) that attenuates or shades an illumination light is contained in a high concentration or even when the photosensitive composition is in the form of a thick film. Specifically provided is a photosensitive composition which comprises the following four components: (1) a radical initiator (A); (2) an acid generator (B) or a base generator (C); (3) a polymerizable substance (D); and (4) a colorant (E), a metal oxide powder (F), or a metal powder (G). Further, the photosensitive composition is characterized in that the radical initiator (A), the acid generator (B), and/or the base generator (C) generates an active species (H) through irradiation with an active ray of light; the active species (H) reacts the radical initiator (A), the acid generator (B), or the base generator (C) to form another species (I); and thus the polymerization of the polymerizable substance (D) by means of the active species (I) proceeds, said active species (H) or (I) being an acid or a base.

A durable ambient light curable waterproof liquid rubber coating with volatile organic compound (VOC) content of less than 450 grams per liter made from ethylene propylene diene terpolymer (EPDM) in a solvent, a photoinitiator, an additive, pigments, and fillers, and a co-agent and a method for making the formulation, wherein the formulation is devoid of thermally activated accelerators.

The present invention relates to a radically polymerizable composition comprising a hydroxylamine ester used to manufacture color filters. The invention further relates to novel hydroxylamine esters. The invention further relates to the use of hydroxylamine esters in all liquid crystal display components requiring post-baking. The present invention relates to a radically polymerizable composition comprising: (a) at least one alkaline developable resin;(b) at least one acrylate monomer;(c) at least a photoinitiator;(d) at least one hydroxylamine ester compound of formula I

A photocurable material for sealing including (A) an oligomer having a weight average molecular weight of 10,000 to 30,000 and having (meth)acryloyl group(s), (B) a (meth)acrylate monomer, (C) a polythiol compound, and optionally (D) a carbodiimide compound enables the provision of a sealing material that has high compression recovery performance, high tensile strength and excellent flexibility, can have low hardness if required, and therefore has excellent sealing properties including air-tightness performance and water-proof performance and undergoes the formation of little surface tacks and the like.

Compositions and methods for adjustable lenses are provided. In some embodiments, the lenses contain a lens matrix material, a masking compound, and a prepolymer. The lens matrix material provides structure to the lens. The masking compound is capable of blocking polymerization or crosslinking of the prepolymer, until photoisomerization of the compound is triggered, and the compound is converted from a first isomer to a second isomer having a different absorption profile. The prepolymer is a composition that can undergo a polymerization or crosslinking reaction upon photoinitiation to alter one or more of the properties of the lenses.

The present disclosure provides a method of providing an adhesive composition comprising the steps of combining crosslinkable composition including: a) a (meth)acryloyl monomer mixture with the b) photocrosslinking agent mixture, and irradiating with UVC radiation to polymerize and crosslink the composition.

1,4 fullerene deriatives useful for solar cells are provided, where their structures allow for straightforward functionalizations to tune their properties in terms of solubility and LUMO energy levels.

The invention discloses a deep-ultraviolet chemically-amplified positive photoresist. The deep-ultraviolet chemically-amplified positive photoresist according to one embodiment of the invention includes a cyclopentenyl pimaric acid, a divinyl ether, a photoacid generator and an organic solvent. The deep-ultraviolet chemically-amplified positive photoresist according to the invention has a good sensitivity and a good transparency.

The present invention relates to photochromic materials that include one or more indeno-fused naphthopyrans that have particular groups at the 7, 11, and 13 positions thereof, and at the position alpha to the oxygen of the pyran ring thereof. With some embodiments, hydrogen or an alkoxy group is bonded to the 7 position, an optionally substituted phenyl is bonded to the 11 position, two alkyl groups are bonded to the 13 position, and two optionally substituted phenyl groups are bonded to the position alpha to the oxygen of the pyran ring of the indeno-fused naphthopyran compound. The 13 position of the indeno-fused naphthopyrans is free of ether groups in which an ether oxygen is bonded to the 13 position, and hydroxyl. The present invention also relates to photochromic articles and compositions that include such indeno-fused naphthopyrans.

Described herein are compounds generally comprising an indeno[2',3':3,4]naptho[1,2-b]pyran structure. Such compounds may be useful for their photochromic properties, and be used in certain photochromic compositions. Such compositions may further comprise other photochromic compositions and/or materials. Additionally, such compounds and/or compositions may be suitable for preparing certain photochromic articles. Also described herein are methods for preparing certain photochromic compounds, compositions, and articles.

Disclosed is a photosensitive resin composition for a color filter and a color filter using the same. The photosensitive resin composition for a color filter includes (A) a dye-polymer composite including a structural unit derived from the compound represented by the following Chemical Formula 1, wherein each substituent is the same as defined in the detailed description; (B) an acryl-based photopolymerizable monomer; (C) a photopolymerization initiator; and (D) a solvent.

Disclosed is a photosensitive resin composition for a color filter including (A) a dye-polymer composite wherein the dye includes a repeating unit derived from a compound represented by the following Chemical Formula 1, wherein in Chemical Formula 1, each substituent is the same as defined in the detailed description; (B) a binder resin; (C) a photopolymerizable monomer; (D) a photopolymerization initiator; and (E) a solvent.

There is intended to provide the novel compounds which generate a base easily when irradiated with long wavelength light (active energy rays), a photobase generator containing the compounds and a photobase generation method, and the present invention relates to the compounds represented by the general formula [1], a photobase generator containing the compounds and a photobase generation method: (wherein, Ar represents any of groups with specific structures selected from the group consisting of an anthracenyl group, an anthraquinonyl group and a pyrenyl group; R1 and R2 each independently represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or represent ones which can form an alicyclic ring containing nitrogen atom(s) or an aromatic ring containing nitrogen atom(s) together with a nitrogen atom to which they are bound, which the rings having 3 to 8 carbon atoms which may have a substituent, R3 and R4 each independently represent a hydrogen atom, a linear, branched or acyclic alkyl group having 1 to 10 carbon atoms).

A photosensitive resin composition for an insulating film of a display device includes (A) an alkali soluble resin including a polybenzoxazole precursor, polyamic acid, polyimide, or a combination thereof; (B) a photosensitive diazoquinone compound; (C) an ultraviolet (UV) absorber having a maximum absorption wavelength of about 300 to about 400 nm; and (D) a solvent. An insulating film and a display device can include the photosensitive resin composition.

A photosensitive resin composition for a color filter includes (A) an acrylic-based binder resin including a structural unit represented by the following Chemical Formula 1, wherein the definitions of R1, R2, R3 and R4 are the same as set forth in specification; (B) an acrylic-based photopolymerizable monomer; (C) a photopolymerization initiator; (D) a colorant; and (E) a solvent.

Provided is a photo-curable transparent resin in which an oxetane monomer for promotion of photo-curing, control of viscosity, and improvement of physical properties is mixed with a photo-cationically polymerizable cyclo-aliphatic epoxy group-containing oligosiloxane resin prepared by a sol-gel reaction. The photo-cationically polymerizable photo-curable transparent resin added with the oxetane monomer provides a cured product having high curing density and retaining excellent mechanical properties, thermal-mechanical properties, and electrical properties.

Polymeric blends having improved flame retardance properties and good ductility at low temperatures are disclosed. The blend is formed from (A) a photoactive additive containing a photoactive group derived from a monofunctional benzophenone; and (B) a polymer resin which is different from the photoactive additive. The additive can be a compound, oligomer, or polymer. When exposed to ultraviolet light, crosslinking will occur between the photoactive additive and the polymer resin, enhancing the chemical resistance and flame retardance while maintaining ductility.

A photocurable adhesive composition is provided, which comprises: a) a (meth)acrylate oligomer having one or more functional groups, b) a mono-functional monomer, a multi-functional monomer, or a mixture thereof, c) a photoinitiator, and d) a plasticizer having a refractive index of no less than 1.48. The photocurable adhesive composition of the present invention has good light transmittance, high refractive index and appropriate flowability and softness, and is easy to be coated and adhered. The photocurable adhesive composition of the present invention can be applied to optical products and simplify the manufacture processes, and provide adhesion property while retaining good reworkability and optical properties.

The present invention provides a dye that is excellent in solubility and heat-resistance, and a novel compound that is suitable for the dye, and specifically provides a yellow dye having a maximum absorption wavelength in the region of 420 to 470 nm. Furthermore, the present invention provides a colored (alkali-developable) photosensitive composition and an optical filter using the dye, and specifically provides a color filter that does not decrease luminance and thus is preferable for an image display device such as a liquid crystal display panel. Specifically, the present invention provides a novel compound represented by the following general formula (1), a dye using the compound, and a colored (alkali-developable) photosensitive composition and a color filter. The content of the above-mentioned general formula (1) is as described in the description.

[Problem] To provide a photocurable sealing material which exhibits stable physical properties, particularly permanent compression set when subjected to a heat resistance test in an atmosphere of 100 to 150° C., and has a stable applying shape and storage stability. [Solution] A photocurable composition containing components (A) to (C) mentioned below, in which the mass ratio of the component (A) to the component (B) is 3:7 to 8:2; component (A): a compound having a polymer of a (meth)acrylic monomer as a main skeleton and having one (meth)acryl group at each of the both terminals;component (B): a compound having a polymer of a (meth)acrylic monomer as a main skeleton and having one (meth)acryl group at only one terminal; andcomponent (C): a photoinitiator.

A description is given of a photoreactive polymer preparable by radical polymerization using at least one photoreactive monomer, where the photoreactive monomer has at least one radically polymerizable C—C double bond, at least one hydrophilic group selected from an ethylene glycol group and polyethylene glycol groups having at least 2 ethylene glycol units, and at least one photoreactive group, the photoreactive group being a photoenolizable carbonyl group.

The present invention relates to the use of polymeric photoinitiators based on polyalkyletherurethane backbones in the production of hydrophilic gels, in particular hydrogels. The invention relates to methods for manufacturing hydrophilic gels using said polymeric photoinitiators, and the hydrophilic gels thus obtained.

A method is described for improving the uniformity over a predetermined substrate area of a spectral response of photonic devices fabricated in a thin device layer. The method includes (i) establishing an initial device layer thickness map for the predetermined area, (ii) establishing a linewidth map for the predetermined area, and (iii) establishing an etch depth map for the predetermined area. The method further includes, based on the initial device layer thickness map, the linewidth map and the etch depth map, calculating an optimal device layer thickness map and a corresponding thickness correction map for the predetermined substrate area taking into account photonic device design data. Still further, the method includes performing a location specific corrective etch process in accordance with the thickness correction map.

Provided is a method of producing an electrophotographic photosensitive member having improved sensitivity and capable of outputting an image having less image defects due to a ghost phenomenon not only under a normal-temperature, normal-humidity environment but also under a low-temperature, low-humidity environment as a particularly severe condition. The method of producing a gallium phthalocyanine crystal includes subjecting a gallium phthalocyanine and a specific amine compound, which are added to a solvent, to a milling treatment to perform crystal transformation of the gallium phthalocyanine. In addition, the gallium phthalocyanine crystal is used in the photosensitive layer of the electrophotographic photosensitive member.

A photoresist composition. The composition has the following: (a) one or more resin binders that include one or more acid sensitive groups and that are substantially free of phenolic groups protected by acetal or ketal groups; (b) one or more photo acid generators, that, upon exposure to a source of high energy, decompose and generate a photoacid strong enough to remove the one or more acid sensitive groups; (c) one or more ionic non-photosensitive additives including an iminium salt; and (d) one or more solvents. There is also a process for patterning relief structures on a substrate employing the photoresist composition.

The present invention relates to a photosensitive composition including an acrylate-based compound having an adamantyl structure. It is possible to manufacture an organic thin film that is easily stripped without decreasing the strength of the thin film by using the photosensitive composition.

Systems and methods for liquid deposition photolithography are described. In particular, some embodiments relate to systems and methods for using photolithography to control the 2D structure of a thin layer of material (e.g., photopolymer) using various masks, projection optics and materials. In one or more embodiments, this thin layer can be manipulated by micro-fluidic techniques such that it can be formed, patterned and post-processed in a liquid environment, vastly simplifying the creation of multi-layer structures. Multiple layers are rapidly built up to create thick structures of possibly multiple materials that are currently challenging to fabricate by existing methods.

A method includes scanning a lithography mask with a repair process, and measuring back-scattered electron signals of back-scattered electrons generated from the scanning. An endpoint is determined from the back-scattered electron signals. A stop point is calculated from the endpoint. The step of scanning is stopped when the calculated stop point is reached.

Disclosed is a positive photosensitive resin composition that includes (A) an alkali soluble resin prepared by a phosphorous-containing diamine represented by the following Chemical Formula 1, (B) a photosensitive diazoquinone compound, and (C) a solvent. A photosensitive resin film prepared using the same and a semiconductor device including the photosensitive resin film are also disclosed. In Chemical Formula 1, each substituent is the same as defined in the detailed description.

Provided are an electrophotographic photosensitive member in which leakage doesn't easily occur, a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member, and a method of manufacturing the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a conductive layer including titanium oxide particle coated with tin oxide doped with a hetero element. When an absolute value of a maximum current amount flowing through the conductive layer in a case of performing a test of applying −1.0 kV including DC voltage to the conductive layer is defined as Ia, and an absolute value of a current amount flowing through the conductive layer in a case where a decrease ratio of a current amount per minute reaches 1% or less for the first time is defined as Ib, the relations of Ia≦6000 and 10≦Ib are satisfied. A volume resistivity of the conductive layer before the test is 1.0×108 Ω·cm to 5.0×1012 Ω·cm.

To provide an amine compound, represented by General Formula (I) below: [In General Formula (I), R1 and R2 represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be identical or different; m and n are an integer of 1 or 0; Ar1 represents a substituted or unsubstituted aromatic hydrocarbon group; Ar2 and Ar3 represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aromatic hydrocarbon group; and Ar1 and Ar2 or Ar2 and Ar3 may bind to each other to form a substituted or unsubstituted heterocyclic group including a nitrogen atom.]

A solution of a gallium phthalocyanine contains a compound of formula (1) and a gallium phthalocyanine of formula (2), H2N—CH2—R1—CH2—NH2 (1) wherein R1 represents a single bond, or a substituted or unsubstituted alkylene group having 1 to 10 main-chain carbon atoms, a substituent of the substituted alkylene group is an alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms and being substituted with an amino group, or a hydroxy group, one of the carbon atoms in the main chain of the alkylene group may be replaced with an oxygen atom, a sulfur atom, or a bivalent group represented by the formula —NR2—, and R2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 3 carbon atoms and being substituted with an amino group, and wherein X1 represents a chlorine atom or hydroxy group.

Provided is a method of producing an electrophotographic photosensitive member having improved sensitivity and capable of outputting an image having less image defects due to a ghost phenomenon not only under a normal-temperature, normal-humidity environment but also under a low-temperature, low-humidity environment as a particularly severe condition. The method of producing a gallium phthalocyanine crystal includes subjecting a gallium phthalocyanine and a specific amine compound, which are added to a solvent, to a milling treatment to perform crystal transformation of the gallium phthalocyanine. In addition, the gallium phthalocyanine crystal is used in the photosensitive layer of the electrophotographic photosensitive member.

There is provided a component mounting apparatus, which includes: a nozzle which sucks a component; a nozzle supporting member, on which the nozzle is installed, which moves in a vertical direction with respect to an upper surface of a substrate on which the component sucked at the nozzle is mounted; an optical system which captures an image of a leading edge portion of the nozzle where the component is sucked in a component mounting operation, from a side direction, such that an optical axis of the optical system is inclined at a predetermined angle with respect to a sucking surface of the nozzle; and an analyzer which analyzes the image of the leading edge portion to determine whether a sucking state of the component sucked by the nozzle is normal or abnormal.

This invention concerns real-time multi-impairment signal performance monitoring. In particular it concerns an optical device, for instance a monolithic integrated photonics chip, comprising a waveguide having an input region to receive a signal for characterization, and a narrow band CW laser signal. A non-linear waveguide region to mix the two received signals. More than one output region, each equipped with bandpass filters that extract respective discrete frequency bands of the RF spectrum of the mixed signals. And, also comprising (slow) power detectors to output the extracted discrete frequency banded signals.

A system for controlling photovoltaic electricity production equipment having photovoltaic modules each equipped with a DC/DC microconverter connected to a DC bus, a DC bus manager, and an inverter for converting the direct current from the photovoltaic panels into alternative current intended for an electrical distribution network. Power is injected into the DC bus when the voltage of the DC bus is less than a minimum voltage until the minimum voltage is reached. Each of the microconverters injects a maximum power from the photovoltaic modules into the DC bus when the voltage of the DC bus is between a first voltage and a second voltage. The injecting of power from the photovoltaic modules into the DC bus is stopped when the voltage of the DC bus is less than a low threshold voltage or greater than a high threshold voltage.

A servo processor for an optical disk drive is provided that includes: an analog-to-digital converter for converting versions of photodetector output signals into digital signals; and a digital signal processor configured to receive the digital signals, the digital signal processor being further configured to determine a focus error signal (FES) and a tracking error signal (TES) from the digital signals, the digital signal processor being further configured to process TES and FES through servo algorithms to produce tracking and focus control signals.

Disclosed is a novel photosensitizer based on polymer derivatives-photosensitizer conjugates for photodynamic therapy capable of being selectively accumulated in cancerous tissues and producing singlet oxygen or free radical by laser irradiation. The polymer derivatives-photosensitizer conjugates for photodynamic therapy are prepared as nano-sized particles, and have excellent selection and accumulation ratio for cancerous tissues. The photosensitizer conjugates can produce singlet oxygen or free radical by a specific laser wavelength. Owing to the excellent selection and accumulation ratio for cancerous tissues, the conjugates minimizes photo-cytotoxicity of the conventional photosensitizer having a low molecular amount. Accordingly, the conjugates are very useful as a photosensitizes for photodynamic therapy with reduced side effects and excellent therapeutic effectiveness.

This invention refers to photo-crosslinked hydrogel materials based in gellan gum suitable for tissue engineering and regenerative medicine applications or as drug delivery systems. Formulations of gellan gum with different degrees of acylation serve as precursor material for insertion of a polymerizable moiety. The materials are capable of free radical polymerization with a photo-initiator at mild temperatures and exposure to ultraviolet light, enabling control of reticulation and withstanding the encapsulation of human and animal cells and/or drugs, and any combination thereof. The physicochemical and biological properties can be adjusted by combining different formulations of gellan gum and reaction conditions. The matrix can be used either as an acellular or cellular system, dispensed manually or automatically by injection and crosslinked directly at the site of application, and can be processed using manual or automated systems in different types of scaffolds, such as hydrogels, fibers, 3D structures and micro- or nanoparticles.