ライフサイエンスコーパス: hydrogel

1 s by using borate ester linkages (Pt-G4K(+)B hydrogel).

2 and initial characterization of a novel DNA hydrogel.

3 d AMP) also convert the solution of 1 into a hydrogel.

4 emains intact and behaves as a pH-responsive hydrogel.

5 of hydrophilic molecules entrained within a hydrogel.

6 RDDs) were prepared and anchored to a RADA16 hydrogel.

7 as drug depot that was then anchored to the hydrogel.

8 capsulated aqueous droplets and the encasing hydrogel.

9 ns of the electrical potential and pH of the hydrogel.

10 od array deposited on the synthetic silicone hydrogel.

11 bedded within permeable agarose and alginate hydrogels.

12 e outcome configurations of planar-patterned hydrogels.

13 icelles, vesicles, hybrid nanoparticles, and hydrogels.

14 he presence of beta-sheets within the hybrid hydrogels.

15 s into physically cross-linked, viscoelastic hydrogels.

16 ioprinting of nonviscous photo-crosslinkable hydrogels.

17 e existed AFM techniques on living cells and hydrogels.

18 , including liquid droplets and fibril-based hydrogels.

19 se of traditional cell-laden photodegradable hydrogels.

20 low-induced gelled materials, such as porous hydrogels.

21 trategies is vital to engineering functional hydrogels.

22 rial field, especially in the preparation of hydrogels.

23 rogramed cells in printed microstructures of hydrogels.

24 The use of zwitterionic hydrogel (a double-sided tape) and commercial superglue

25 established; within a dilute collagen-type I hydrogel, a novel clonal strain of rat cancer-associated

26 The goal of this project was to create hydrogels, a type of soluble biopolymer delivery system

27 The hydrogel actuators and robots can maintain their robustn

28 r demonstrate that the agile and transparent hydrogel actuators and robots perform extraordinary func

29 However, existing hydrogel actuators, mostly osmotic-driven, are intrinsic

30 tegration of the ND-Dex complex within GelMA hydrogels allowed a higher retention of Dex over time, r

31 The hydrogel allows exquisite control over the chemical and

32 ion of P5P to the solution of 1 results in a hydrogel almost instantly (about 4 seconds).

33 ese results demonstrate that self-assembling hydrogel-anchored drug-loaded RDDs are promising for loc

34 his report reviews recent advances made with hydrogel and graphene materials for the development of h

35 idase (GOD) were electrodeposited within the hydrogel and the activity of the bi-enzymatic system was

36 ulated by both the concentration of 1 in the hydrogel and the intensity of the light.

37 Existing hydrogels and composites partially achieve some of the m

38 e demonstrate that CrvA promotes motility in hydrogels and confers an advantage in host colonization

39 al approaches to responsive helices based on hydrogels and liquid crystalline polymers have been repo

40 To accomplish precision molding of hydrogels and successful integration with microfluidics,

41 icle introduces the properties of injectable hydrogels and summarizes their versatile application in

42 resolution 3-D photoclick derivatization of hydrogels and tissues.

43 ng of their xerogels, XGh (xerogel made from hydrogel) and XGo (xerogel made from organogel).

44 increased upon mechanical stimulation with a hydrogel, and single cells altered protein concentration

45 Allergen challenge was continued during HOCl hydrogel application.

46 0 protein identifications are made from each hydrogel, approximately 20% of the proteins identified a

47 y molded tubular channels inside a synthetic hydrogel are seeded with endothelial cells and subjected

48 ourses for biological experiments using this hydrogel are variable, and thus they may range from hour

49 The GA-functionalized injectable hydrogels are also found to contribute significantly to

50 A number of injectable hydrogels are approved by FDA as surgery sealants, tissu

51 Fibrillar type I collagen-based hydrogels are commonly used in tissue engineering and as

52 factors, such as peptides and proteins, onto hydrogels are critical in designing materials with biolo

53 trong, tough, stretchable, and self-adhesive hydrogels are designed with intrinsically unstructured p

54 s and functional role of these intracellular hydrogels are difficult to study, primarily due to techn

55 Hydrogels are formed from hydrophilic polymer chains sur

56 While the methyl asparagusic acid-derived hydrogels are highly dynamic, adaptable, and self-healin

57 These hydrogels are often designed with a specific biological

58 gned to have load bearing properties whereas hydrogels are proposed to support in vitro cell culture.

59 Hydrogels are used in a wide variety of biomedical appli

60 eedstock, is used to develop a biocompatible hydrogel as anti-infective ointment.

61 the use of electrodeposited calcium alginate hydrogels as a biocompatible matrix in the development o

62 ies is driving the development of injectable hydrogels as new medical devices for controlled delivery

63 ing and pH-responsive characteristics of the hydrogel, as well as cell viability after treatment with

64 e CB[8] ternary complex for the formation of hydrogels, as these gels exhibit unprecedented pressure-

65 (FRAP) to probe chain mobility in reversible hydrogels assembled from engineered proteins bearing ter

66 nic segments that form beta-sheet-structured hydrogel assemblies via polyion complexation when mixed

67 <5min from a liquid at room temperature to a hydrogel at body temperature.

68 one marrow stem cells were mingled with silk hydrogels at the concentrations of 1.0 x 10(5)/mL, 1.0 x

69 We fabricate a freestanding and flexible hydrogel based platform using 3D bioprinting.

70 cartilage is achieved using polyelectrolyte hydrogels based on polyvinyl alcohol and polyacrylic aci

71 od using molecular self-assembly to generate hydrogel-based 3D architectures that resembles the appea

72 porous nature and excellent water retention, hydrogel-based biomaterials can mimic critical propertie

73 y, we engineered a polyethylene glycol (PEG) hydrogel-based subunit vaccine for the delivery of an an

74 ty of the printed cells, and the self-folded hydrogel-based tubes support cell survival for at least

75 g an inDrops platform (1 d); (ii) performing hydrogel bead synthesis (4 d); (iii) encapsulating and b

76 lized 3D vascular networks within cell-laden hydrogel biomaterials is introduced.

77 ite allergen and treated topically with HOCl hydrogel both preventively and therapeutically against e

78 ave developed a novel moldable nanocomposite hydrogel by combining dopamine-modified poly(ethylene gl

79 is of entirely protein-based photoresponsive hydrogels by covalently polymerizing the adenosylcobalam

80 incorporated into G-quadruplex G4K(+) borate hydrogels by using borate ester linkages (Pt-G4K(+)B hyd

81 ous configurations of an identical patterned hydrogel can be programmed by the pre-swelling step with

82 ngin-carrying CHC-beta-GP-glycerol colloidal hydrogel can be used to inhibit induction of experimenta

83 hese results suggest that conventional GelMA hydrogels can be coupled with conjugated NDs to develop

84 nt beta-sheet cross-links to reassemble, the hydrogels can self-heal after being strained to failure,

85 ry system is comprised of a thermoresponsive hydrogel carrier and drug-loaded polymer microspheres.

86 , self-assembly, electrophoretic deposition, hydrogel casting, doctor blading, and many others.

87 liquid to solid phase change of a composite hydrogel (CH) ink.

88 overall diameter following the addition of a hydrogel coating.

89 Endovascular embolization with hydrogel coils is an effective and safe treatment method

90 Hydrogel coils were created to improve the chances of an

91 y-six cerebral aneurysms were embolized with hydrogel coils, which expand in contact with blood.

92 tment of intracranial aneurysms with the use hydrogel coils.

93 Together, these results identify GelMA hydrogel combined with hDPSC/HUVECs as a promising new c

94 and electrical potential gradients, when the hydrogel comes in contact with the urea-rich solution, s

95 nts of ions between miniature polyacrylamide hydrogel compartments bounded by a repeating sequence of

96 The resulting hydrogel composed of physically self-assembled CarHC pol

97 rug-dose dependent but unaffected by the H9e hydrogel concentration, indicating that the hydrogel did

98 at increased HA leads to mechanically softer hydrogels, consistent with our model.

99 We synthesized hybrid hydrogels consisting of a poly(gamma-glutamic acid) poly

100 Hydrogels consisting of carboxylic acid groups and N-iso

101 l as cell viability after treatment with the hydrogel containing naringin, were evaluated in vitro.

102 nfarct vascularization compared to nonporous hydrogel controls and stroke only controls.

103 Using a dialysis method, we found that H9e hydrogel could not significantly inhibit the diffusion o

104 othesized that addition of MMP-20 to CS-AMEL hydrogel could reinforce the newly grown layer.

105 , our results suggest that Bio-IL conjugated hydrogels could be implemented and readily tailored to d

106 The engineered hydrogels could support the growth and function of prima

107 complete post-swelling removal, without the hydrogel cracking or crumbling.

108 Based on the cyclic deformation, the hydrogel crawlers can move peristaltically in a confined

109 Hydrogels crosslinked by allyl-sulfide-containing molecu

110 ent polyurethane hydrogels investigated, the hydrogel D1 featuring the highest water uptake was found

111 The amount of the caffeine released from hydrogel decreased by citrate cross-linking and was high

112 dures for quantitative assessment of in vivo hydrogel degradation by imaging of fluorescently derivat

113 The mechanical properties of agarose-derived hydrogels depend on the scaffolding of the polysaccharid

114 The properties of the resulting hydrogels depend sensitively on the structures of 1,2-di

115 the dramatically different properties of the hydrogels derived from the two different dithiolanes.

116 ue features of the beta-sheet-structured PIC hydrogels described here highlight the potential of harn

117 fications are still achieved at the smallest hydrogel diameters of 260 mum.

118 hydrogel concentration, indicating that the hydrogel did not inhibit the drug.

119 erties of soft samples like living cells and hydrogels directly from conventional AFM F-Z experiments

120 Here Pham et al. show that when hydrogel drops are placed on a rapidly heated plate they

121 or/tissue grafts, can be encapsulated in the hydrogels during hydrogel formation and then analyzed fo

122 verse as polymer chemistry, biomaterials and hydrogels, dynamic combinatorial chemistry, organic synt

123 t the interface between each droplet and the hydrogel; each bilayer then incorporated bR.

124 he high stretchability and robustness of the hydrogel-elastomer hybrids prevent leakage of cells from

125 ed on stretchable, robust, and biocompatible hydrogel-elastomer hybrids that host various types of ge

126 n tissue growth, and the continued growth of hydrogel enabled by diffusion of monomers/cross-linkers

127 ROS sensor comprising an ascorbic-acid-based hydrogel encapsulating luminescent amphiphilic carbon-do

128 of photochemical reactions to create dynamic hydrogel environments, and how these dynamic environment

129 the fluorophore part of camptothecin and the hydrogel, especially at concentration 0.25 and 0.5 wt%.

130 ling peptide hydrogel has been reported; the hydrogel exhibited physiological properties superior to

131 Bio-IL conjugated hydrogels exhibited a wide range of highly tunable physi

132 photocytotoxic index <2, whereas Pt-G4K(+)B hydrogels exhibited more potent photocytotoxicity (IC50

133 DNA molecules can induce 100-fold volumetric hydrogel expansion by successive extension of cross-link

134 AFM images, a PGworks solution triggered H9e hydrogel fiber aggregation and forms a 3D matrix suitabl

135 The hydrogel fibers consist of poly(acrylamide-co-poly(ethyl

136 We demonstrate application of the C-dot-hydrogel for evaluating the efficacy of a chemotherapeut

137 genase embedded in a viologen-modified redox hydrogel for the fabrication of a sensitive hydrogen bio

138 Recent works have attempted to specialize hydrogels for cancer research; we comprehensively review

139 Research on hydrogels for drug, factor, nanoparticle, and stem cell

140 stimulus-responsive copolymer vesicles (and hydrogels) for targeted delivery and controlled release

141 embly was found to be required for efficient hydrogel formation and provided distinct and useful prop

142 can be encapsulated in the hydrogels during hydrogel formation and then analyzed for cellular respon

143 Hydrogels formed by the self-assembly of low-molecular-w

144 tions such as hollow, coated, dissolving and hydrogel forming microneedles.

145 the hydrogel scaffold; as a consequence, the hydrogel framework collapses resulting in aggregation of

146 with more homogeneous pores compared to the hydrogel from oat cellulose fibers.

147 The hydrogel from rice cellulose fibers had a network struct

148 en gelation to obtain chemically crosslinked hydrogels from defect-rich 2D molybdenum disulfide (MoS2

149 sses thermoplastics, thermosets, elastomers, hydrogels, functional polymers, polymer blends, composit

150 injectable system with photo-cross-linkable hydrogel (G) and nanodiamond (ND) technology to facilita

151 strategy of pre-mingling stem cells with the hydrogel had the effect of delivering more stem cells fo

152 Previously, a self-assembling peptide hydrogel has been reported; the hydrogel exhibited physi

153 ic cues and structural complexity within the hydrogels has limited their functions.

154 thylsiloxane (PDMS) and Polyacrylamide (PAm) hydrogel have been chosen as soft polymers to be moulded

155 microscopic fibers present in organogel and hydrogel have different morphology as was evident from s

156 Synthetic hydrogels have been developed to recapitulate many of th

157 erties, genetically engineered protein-based hydrogels have emerged as a promising candidate for biom

158 mand for creating stimuli-responsive "smart" hydrogels, here we show the synthesis of entirely protei

159 the long-range ordering observed within the hydrogel hybrid material.

160 when pericytes undergo chondrogenesis in the hydrogel in the absence of induction media.

161 fabrication and application of nanocomposite hydrogels in tissue engineering applications are describ

162 ies, such as RNA granules, are known to form hydrogels in vitro.

163 Here we investigated the use of viscoelastic hydrogels, in which stresses are relaxed over time and w

164 ation and characterization of the guest-host hydrogels, including assessment of their rheological pro

165 ided distinct and useful properties to these hydrogels, including self-healing after deformation, mic

166 addition, the in vivo retention of injected hydrogel-incorporated RDDs was significantly longer than

167 d RDDs was significantly longer than that of hydrogel-incorporated unmodified DDs.

168 Cultivation of LEPC on fibrin-based hydrogels incorporating LN-511-E8 resulted in firm integ

169 ategy for a rapid induction of protein-based hydrogels inside living cells that explores the chemical

170 ediate polymer became a pH-sensitive anionic hydrogel insoluble in either aqueous or organic solvents

171 ing property to swelling of the pore-filling hydrogel into the damage site, strong hydrogen bonding,

172 at the injection of a porous hyaluronic acid hydrogel into the stroke cavity significantly reduces th

173 Among different polyurethane hydrogels investigated, the hydrogel D1 featuring the hi

174 mically cross-linked biocompatible polymeric hydrogel is developed.

175 The urea sensitivity of the hydrogel is usually characterized by the states of ioniz

176 (NPC) culture within three-dimensional (3D) hydrogels is an attractive strategy for expanding a ther

177 The utility of these small hydrogels is demonstrated through the analysis of sub re

178 sed on printing of shape-morphing biopolymer hydrogels, is developed for the fabrication of hollow se

179 ing units with beta-sheet peptides to form a hydrogel, it can easily be modified further to incorpora

180 ly cross-linked and is easily converted into hydrogels, it represents a new dual-responsive materials

181 A poly(organophosphazenes) hydrogel lacking the imidazole moiety, which physically

182 med in the cytosol resembles a physiological hydrogel-like entity that acts as a size-dependent molec

183 structures of responsive materials including hydrogels, liquid-crystal elastomers, shape-memory polym

184 ative agarose, while the considerably softer hydrogels made from carboxylated agarose use a scaffold

185 ynthetic pathway allowed for the creation of hydrogel materials under physiological conditions at low

186 viability (>95% after 4 days) in these novel hydrogel materials.

187 s also facilitates fabricating them as solid hydrogel matrices by adding divalent calcium ions.

188 sion of camptothecin encapsulated inside the hydrogel matrix.

189 Triggerable tough hydrogels may be applied in myriad of applications, incl

190 ting sequence of cation- and anion-selective hydrogel membranes.

191 Here we develop a biphasic hydrogel methodology, which along with automated analysi

192 functional conducting polyacrylic acid (PAA) hydrogel (MFH) integrated with reduced grapheme oxide (r

193 Hydrogel micropatches enable noninvasive collection of s

194 Hydrogels mimic many of the physical properties of soft

195 n Drosophila melanogaster larvae dwelling in hydrogels mimicking their natural habitat.

196 The dependence of the hydrogel motility on the pattern structures and lubricat

197 , enable the formation of stimuli responsive hydrogel nanocomposite membranes, and can be easily modi

198 the physical and chemical properties of the hydrogel network can be controlled.

199 sical and mechanical properties of the GelMA hydrogel network.

200 The hydrogels not only exhibit thermo-, photo-, and mechano-

201 ged, non-spherical polyethylene glycol (PEG) hydrogel NPs by endothelial cells (ECs) cultured in a mi

202 Overall, the nanoengineered hydrogel obtained from vacancy-driven gelation is mechan

203 gle-stranded alpha-helix in the highly rigid hydrogel of native agarose, while the considerably softe

204 Hydrogel optical fibers are utilized for continuous gluc

205 material derived either as a supramolecular hydrogel or single crystals.

206 can tailor the mechanical properties of the hydrogels over an order of magnitude range of 10-200 kPa

207 LuPc2 was then doped to form multifunctional hydrogel (PAA-rGO/VS-PANI/LuPc2-MFH).

208 Hydrogel particles are versatile materials that provide

209 The favorable properties of hydrogel particles depend largely on their size, and par

210 size of polypeptide-based, thermoresponsive hydrogel particles, from the nano- to microscale, using

211 The C-dot-hydrogel platform exhibits high sensitivity and detected

212 Hydrogels play a central role in a number of medical app

213 , and assessed the effect of thermosensitive hydrogels (poly(lactic-co-glycolic acid)-b-poly(ethylene

214 f pH-responsive polymeric carriers including hydrogels, polymer-drug conjugates, micelles, dendrimers

215 The hydrogel polymeric network is formed via a laccase-media

216 We show that oxygen plays a role in hydrogel polymerization which is mechanistically similar

217 The results of this study show that hydrogel pore-filled membranes are a promising new class

218 The hydrogels prepared from the cellulose extracted from ric

219 Treatment with HOCl hydrogel prevented the development of lesions and scratc

220 ssing of amelogenin by MMP-20 in the CS-AMEL hydrogel prevented undesirable protein occlusion within

221 A lithium-chloride-containing hydrogel printing ink is developed and printed onto trea

222 These newly improved methods to the hydrogel process will allow researchers to target smalle

223 Human cell-seeded GelMA hydrogels promoted the establishment of well-organized n

224 The hydrogel provides sustainable supplies of water and nutr

225 The resulting hydrogel provides sustained-release of protein for more

226 egy to engineer pre-vascularized, cell-laden hydrogel pulp-like tissue constructs in full-length root

227 ing the hydrophobic polyester content in the hydrogel reduced the swelling velocity to a rate and vol

228 apsulation of flavor nanoemulsions in filled hydrogels reduces the release of limonene.

229 The hydrogels released 50% of their payload within 30min and

230 The hydrogel reported here provides a new material platform

231 assembly of stimuli-responsive proteins into hydrogels represents a versatile strategy for designing

232 Thanks to the unique properties of hydrogels, researchers have made significant progress in

233 Measurements of soft hydrogel samples with a well-defined elastic modulus usi

234 artially randomly oriented (PRO) crystalline hydrogel samples.

235 rent study, a polymeric drug depot-anchoring hydrogel scaffold was developed for the sustained releas

236 that, with the assist of a thermoreversible hydrogel scaffold, the bioprocessing including iPSC expa

237 et dental pulp stem cells, encapsulated in a hydrogel scaffold, were injected into half the experimen

238 dation of the ascorbic acid units within the hydrogel scaffold; as a consequence, the hydrogel framew

239 Integrin binding to bioengineered hydrogel scaffolds is essential for tissue regrowth and

240 Here, we 3D print microporous hydrogel scaffolds to test how varying pore geometry, ac

241 The encapsulation of single cells in tunable hydrogels should find use in a variety of tissue enginee

242 and encapsulated cells in the nanocomposite hydrogels show high viability.

243 Most notably, Pt-DA and Pt-G4K(+)B hydrogels show selective phototoxicity for cancer cells

244 These hybrid conductive composite hydrogels showed bi-stable states and tunable resistance

245 on of monomers/cross-linkers into the porous hydrogel similar to the mechanisms of tissue growth enab

246 oss-linker and monomer into a prepolymerized hydrogel sink results in a tunable stiffness gradient at

247 Naringin-carrying CHC-beta-GP-glycerol hydrogel sites showed significantly reduced periodontal

248 In situ hydrogel softening (from ca. 14 to 3.5 kPa) led to a dec

249 progress has been achieved using injectable hydrogels, some challenging issues must still be overcom

250 we report a supramolecular polymer-colloidal hydrogel (SPCH) composed of 98 wt % water that can be re

251 edding of the probes and reference dyes into hydrogel spots on a plastic strip yielded a test strip t

252 he responsive behavior of the urea-sensitive hydrogel subject to the urea stimulus, including the dis

253 Its unique properties enable the use of this hydrogel system for numerous applications, such as injec

254 Such a hydrogel system pioneers the study of active motile syst

255 The design of injectable hydrogel systems addresses the growing demand for minima

256 s can be reproduced in other polyelectrolyte hydrogel systems to fabricate biomimetic cellular scaffo

257 In two additional hydrogel systems, permitting NPC-mediated matrix remodel

258 s, they are used as elastomeric materials or hydrogel systems.

259 Recently, hydrogel technologies have been developed that perform s

260 This novel lignin-based hydrogel tested in-vivo has shown the abilities to preve

261 l. (2016) describe a fully defined synthetic hydrogel that mimics the extracellular matrix to support

262 d by incorporating 1.Eu into water-permeable hydrogels that can be utilized as an alternative coating

263 Shape-changing hydrogels that can bend, twist, or actuate in response t

264 ously reported gelatin-based O2-controllable hydrogels that can provide hypoxic microenvironments in

265 with microfluidics, we developed a class of hydrogels that could be macromolded and micromolded with

266 We developed a class of hyaluronic acid (HA) hydrogels that form through noncovalent guest-host inter

267 and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment.

268 o previous realizations of this chemistry in hydrogels, the dry nature of the network enables larger

269 biocompatible polymer matrices (polyurethane hydrogels), thus enabling continuous measurements of aqu

270 esulted in enough mechanical strength of the hydrogel to allow for complete post-swelling removal, wi

271 binant human MMP-20 was added to the CS-AMEL hydrogel to cleave full-length amelogenin during the gro

272 suggested to be encapsulated and cultured in hydrogel to mimic the natural microenvironment of tumors

273 wherein 2D graphenes are hybridized with 3D hydrogels to develop the next generation biosensors and

274 The ability of the hydrogels to encapsulate the orange oil and release the

275 The hydrogel transitioned from a reversibly cross-linked net

276 s, owing to the anti-fatigue property of the hydrogel under moderate stresses.

277 he self-assembly to result in supramolecular hydrogels upon mixing, aromatic-aromatic interactions pr

278 n and supports the fabrication of individual hydrogels using the small punch biopsies.

279 Conventional hydrogels usually possess limited mechanical strength an

280 A covalently cross-linked CarHC hydrogel was also designed to encapsulate and release bu

281 PAm hydrogel was also printed using collagen coated micro-gr

282 The hydrogel was capable of down regulating the expression l

283 The hydrogel was consistently fluidic at 4 degrees C but rap

284 The hydrogel was made of amphipathic carboxymethyl-hexanoyl

285 the in vitro leakage of RDDs from the RADA16 hydrogel was significantly less than that of the unmodif

286 Hydrogel was subgingivally delivered when experimental p

287 Cells encapsulated in the hydrogel were cultured in the microwells of a paper subs

288 e design and synthesis of polypseudorotaxane hydrogels, which are composed of alpha-cyclodextrins and

289 iocompatibility of the naturally polymerized hydrogel with encapsulated RI promotes the protection of

290 Here, the authors develop a drug-loaded hydrogel with high strength to withstand long-term gastr

291 lf-healing polymer-beta-sheet peptide hybrid hydrogel with tailorable mechanical properties is a prom

292 ells were simultaneously embedded in the H9e hydrogel with the initialization of hydrogelation.

293 ion of imidazole poly(organophosphazenes), a hydrogel with thermosensitive sol-gel transition behavio

294 The nanoemulsions were encapsulated into hydrogels with a mean diameter of 768+/-36nm.

295 from rice and oat husks were used to produce hydrogels with poly (vinyl alcohol).

296 st method was used to produce polyacrylamide hydrogels with stiffness gradients of 0.5, 1.7, 2.9, 4.5

297 The hydrogels with stimulus-responsive swelling properties h

298 t stoichiometry, allowing the preparation of hydrogels with tailored properties.

299 In hydrogels with variable HA content, we confirmed that in

300 from which it can be extruded directly as a hydrogel without any chemical reactions or further treat